Kosmos Energy Ltd.

1. Organization

Kosmos Energy Ltd. is incorporated in the State of Delaware as a holding company for Kosmos Energy Delaware Holdings, LLC, a Delaware limited liability company. As a holding company, Kosmos Energy Ltd.’s management operations are conducted through a wholly-owned subsidiary, Kosmos Energy, LLC. The terms “Kosmos,” the “Company,” “we,” “us,” “our,” “ours,” and similar terms refer to Kosmos Energy Ltd. and its wholly-owned subsidiaries, unless the context indicates otherwise.

Kosmos Energy is a leading deepwater exploration and production company focused on meeting the world’s growing demand for energy. We have diversified oil and gas production from assets offshore Ghana, Mauritania, Senegal and the Gulf of America. Additionally, in the proven basins where we operate, we are advancing high-quality development opportunities which have come from our exploration success. Kosmos is listed on the NYSE and LSE and is traded under the ticker symbol KOS.

Kosmos is engaged in a single line of business, which is the exploration, development, and production of oil and natural gas. Substantially all of our long-lived assets and all of our product sales are related to operations inthree geographic areas: Ghana, Mauritania/Senegal and the Gulf of America.

2. Accounting Policies

General

The interim consolidated financial statements included in this report are unaudited and, in the opinion of management, include all adjustments of a normal recurring nature necessary for a fair presentation of the results for the interim periods. The results of the interim periods shown in this report are not necessarily indicative of the final results to be expected for the full year. The interim consolidated financial statements were prepared in accordance with the requirements of the SEC for interim reporting. As permitted under those rules, certain notes or other financial information that are normally required by GAAP have been condensed or omitted from these interim consolidated financial statements. These interim consolidated financial statements and the accompanying notes should be read in conjunction with our audited consolidated financial statements for the year ended December 31, 2025, included in our annual report on Form 10-K.

Reclassifications

Certain prior period amounts have been reclassified to conform with the current presentation. Such reclassifications had no significant impact on our reported net income (loss), current assets, total assets, current liabilities, total liabilities, stockholders’ equity or cash flows.

Cash, Cash Equivalents and Restricted Cash

Cash and cash equivalents include demand deposits and funds invested in highly liquid instruments with original maturities of three months or less at the date of purchase. When our debt cover ratio exceeds 2.50 x, we are required under the Facility to maintain a restricted cash balance that is sufficient to meet the payment of interest and fees for the nextsix-month period on the 7.750% Senior Notes, the 7.500% Senior Notes, the 8.750% Senior Notes and the 3.125% Convertible Senior Notes or the Facility, whichever is greater. During the first quarter of 2025, the Facility lenders waived the requirement to maintain a restricted cash balance until the March 31, 2026 financial covenant test date. During the second quarter of 2026, the Facility lenders agreed to reduce the amount of the required restricted cash balance to three months of interest and fees until the September 30, 2026 financial covenant test date, after which the amount of the required restricted cash balance will be determined as usual. Our debt cover ratio for the most recent March 31, 2026 financial covenant test date exceeded 2.50 x and the estimated restricted cash funding requirement is approximately $23.5 million. As of June 30, 2026, we have funded approximately $23.5 million into the debt service reserve account as required under the terms of the Facility. Restricted cash – long-term primarily represents cash and cash equivalents collateralized, in accounts held by us, as required to support existing performance obligations in the Gulf of America.

Inventories

Inventories consisted of $132.4 million and $144.9 million of materials and supplies and $7.5 million and $27.7 million of hydrocarbons as of June 30, 2026 and December 31, 2025, respectively. The Company’s materials and supplies inventory primarily consists of casing and wellheads and is stated at the lower of cost, using the weighted average cost method, or net realizable value.

Hydrocarbon inventory is carried at the lower of cost, using the weighted average cost method, or net realizable value. Hydrocarbon inventory costs include expenditures and other charges incurred in bringing the inventory to its existing condition. Selling expenses and general and administrative expenses are reported as period costs and excluded from inventory costs.

Assets and Liabilities Held for Sale

The Company classifies disposal groups as held for sale in the period in which all of the following criteria are met: (1) management, having the authority to approve the action, commits to a plan to sell the disposal group; (2) the disposal group is available for immediate sale in its present condition subject only to terms that are usual and customary for sales of such disposal groups; (3) an active program to locate a buyer or buyers and other actions required to complete the plan to sell the disposal group have been initiated; (4) the sale of the disposal group is probable, and the transfer of the disposal group is expected to qualify for recognition as a completed sale, within one year, except if events or circumstances beyond the Company’s control extended the period of time required to sell the disposal group beyond one year; (5) the disposal group is being actively marketed for sale at a price that is reasonable in relation to its current fair value; and (6) actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn.

A disposal group that is classified as held for sale is initially measured at the lower of its carrying amount or fair value less any costs to sell. Any loss resulting from this measurement is recognized in the period in which the held for sale criteria are met. Subsequent changes in fair value of a disposal group less any costs to sell are reported as an adjustment to the carrying amount of the disposal group, as long as the new carrying amount does not exceed the carrying amount of the assets at the time it was initially classified as held for sale. Depreciation, depletion and amortization expense is not recorded on assets to be divested once they are classified as held for sale. In the initial period in which the disposal group meets the criteria to be classified as held for sale, the assets and liabilities of the disposal group are separately presented as assets held for sale and liabilities held for sale, respectively, in the Consolidated Balance Sheets.

Revenue Recognition

Our oil and gas revenues are recognized when hydrocarbons have been sold to a purchaser at a fixed or determinable price, title has transferred and collection is probable. Certain revenues are based on contracts with provisional pricing and quantity optionality which contain a derivative that is separated from the host contract for accounting purposes. The host contract is the receivable from sales at the spot price on the date of sale. The derivative, which is not designated as a hedge, is marked to market through oil and gas revenue each period until the final settlement occurs, which generally is limited to the month of or month after the sale.

Oil and gas revenue is composed of the following:

Concentration of Credit Risk

Our revenue can be materially affected by current economic conditions and the price of oil and natural gas. However, based on the current demand for crude oil and natural gas and the fact that alternative purchasers are readily available, we believe that the loss of our purchasers and/or of the purchasers identified by our marketing agents would not have a long‑term material adverse effect on our financial position or results of Ghana operations. Customers in our Gulf of America and Mauritania | Senegal business units that comprise 10% or more of our total consolidated oil and gas revenue for the three and six months ended June 30, 2026 and 2025, are shown below.

Recent Accounting Standards

Not Yet Adopted

In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses”. The amendments in ASU 2024-03 require more detailed disclosures about specified categories of costs and expenses included in certain expense captions presented on the face of the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The Company is currently assessing the impact of this standard on its financial statement disclosures.

In November 2024, the FASB issued ASU 2024-04, “Debt - Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments.” The amendments in ASU 2024-04 clarify the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion. The amendments in the ASU are effective for annual periods beginning after December 15, 2025. Early adoption is permitted, however, we do not plan to early adopt ASU 2024-04. The Company is currently assessing the impact this standard will have on its consolidated financial statements.

3. Acquisitions and Divestitures

On February 24, 2026, the Company entered into a Share Sale and Purchase Agreement with a subsidiary of Panoro Energy ASA for the sale of all of our 40.4% participating interest in the Ceiba Field and Okume Complex production assets located in Block G offshore Equatorial Guinea. The transaction closed on June 16, 2026.

Pursuant to the terms of the purchase agreement, Kosmos received final cash consideration of approximately $127.0 million, based on the initial purchase price of $180.0 million reduced by certain purchase price adjustments totaling approximately $53.0 million. The Company is also entitled to future contingent consideration of up to $39.5 million, comprised of $12.5 million linked to future production performance at the Ceiba field, and $9.0 million payable in each of the years 2027, 2028 and 2029, subject to certain production and oil price thresholds.

The proceeds from the transaction were used to repay borrowings under the Facility in June 2026.

Management considers the assets and liabilities in the Ceiba Field and Okume Complex production assets located in Block G offshore Equatorial Guinea included in the Share Sale and Purchase Agreement as a disposal group. The disposal group had previously been classified as held for sale. The following table summarizes the carrying amounts of the major classes of assets and liabilities included in the disposal group as of the date of sale:

Upon closing, the Company recognized a gain on sale of assets of approximately $9.4 million, representing the excess of net proceeds received over the carrying value of the disposal group. The Company evaluated the future contingent consideration and determined that no amounts were recognized at closing as realization is contingent upon future production and commodity price conditions. Any contingent consideration will be recognized when realized. The divestiture does not meet the criteria to be reported as discontinued operations as it does not represent a strategic shift for the Company. Accordingly, the operating results for the disposal group are included in continuing operations in the Company’s Consolidated Statement of Operations through the date of sale in June 2026.

4. Receivables

Receivables consisted of the following:

The Company’s joint interest billings consist of receivables from partners with interests in common oil and gas properties operated by the Company for shared costs. Joint interest billings are classified as current and long-term receivables based on when collection is expected to occur.

Long-term receivables

In February 2019, Kosmos and BP signed Carry Advance Agreements with the national oil companies of Mauritania and Senegal obligating us to finance a portion of the respective national oil company’s share of certain development and production costs incurred for the GTA Phase 1 project through the Commercial Operations Date of the Gimi FLNG vessel. The Commercial Operations Date of the Gimi FLNG vessel was achieved in June 2025. As of June 30, 2026 and December 31, 2025, the balance due from the national oil companies including accrued interest was $450.9 million and $437.1 million, respectively, which is classified as Long-term receivables in our consolidated balance sheets. Interest income on the long-term notes receivable was $7.0 million and $6.2 million for the three months ended June 30, 2026 and 2025, respectively, and $13.8 million and $11.5 million for the six months ended June 30, 2026 and 2025.

5. Property and Equipment

Property and equipment is stated at cost and consisted of the following:

We recorded depletion expense of $111.8 million and $141.7 million for the three months ended June 30, 2026 and 2025, respectively, and $223.5 million and $253.1 million for the six months ended June 30, 2026 and 2025, respectively. During the six months ended June 30, 2026, the decrease in oil and gas properties, net is primarily due to the sale of the Ceiba and Okume Complex production assets located in Block G offshore Equatorial Guinea in June 2026. See Note 3 - Acquisitions and Divestitures. Additions to our proved properties during the six months ended June 30, 2026 primarily related to infill development costs in the Jubilee Field in Ghana and at Winterfell-5 in the Gulf of America. Additionally, in February 2026, Tullow Oil plc, as Operator of the TEN partnership, executed the final Sale and Purchase Agreement enabling the partnership to acquire the TEN FPSO from MODEC, Inc. at the end of its current lease in 2027 for a gross purchase price of $205.0 million. As a result, proved property additions for the period ended June 30, 2026 include $88.2 million for our proportionate share of the finance lease asset, with a corresponding finance lease liability in accrued liabilities. These non-cash impacts are excluded from the statement of cash flows.

6. Suspended Well Costs

The following table reflects the Company’s capitalized exploratory well costs on drilled wells as of and during the six months ended June 30, 2026.

The following table provides an aging of capitalized exploratory well costs based on the date drilling was completed and the number of projects for which exploratory well costs have been capitalized for more than one year since the completion of drilling:

As of June 30, 2026, the projects with exploratory well costs capitalized for more than one year since the completion of drilling are related to the Tiberius discovery in Keathley Canyon Block 964 in the Outer Wilcox play in the Gulf of America.

Tiberius Discovery — In July 2023, we spud the Tiberius infrastructure-led exploration prospect located in Block 964 of Keathley Canyon in the Gulf of America, which encountered hydrocarbon pay. Initial fluid and core analysis supports the production potential of the well, with characteristics analogous with similar nearby discoveries in the Wilcox trend. In July 2026, we completed a farm-out of Tiberius, reducing our interest to 33.34%. The Tiberius project is being progressed as a phased development. A production handling agreement for the Oxy operated Lucius platform was signed in the third quarter of 2025, contracts for the fabrication and installation of the Tiberius subsea production system have been executed and a final investment decision for the development was achieved by the partnership in March 2026.

7. Leases

We have commitments under operating leases primarily related to office leases and as well as the commitment under the TEN FPSO finance lease. Our leases have initial lease terms ranging fromone year toten years. Certain lease agreements contain provisions for future rent increases.

Other information related to operating and finance leases at June 30, 2026 and December 31, 2025, is as follows:

(1) Represents $88.2 million of proved property additions or our proportionate share of the TEN FPSO finance lease asset offset by depletion expense of approximately $18.7 million for the period ended June 30, 2026.

Future minimum rental commitments under our leases as of June 30, 2026, are as follows:

(1) Does not include purchase commitments for jointly owned fields and facilities where we are not the operator and excludes commitments for exploration activities, including well commitments, in our petroleum contracts.

(2) Represents the period July 1, 2026 through December 31, 2026

8. Debt

(1)Includes $21.7 million and $24.3 million of unamortized deferred financing costs related to the Facility, $8.0 million and $10.4 million of unamortized deferred financing costs and discounts related to the Senior Notes, and $8.0 million and $9.0 million of unamortized deferred financing costs related to the 3.125% Convertible Senior Notes, $6.3 million and $0.8 million of unamortized deferred financing costs related to the 11.250% Senior Secured Bonds and $3.5 million and $3.0 million of unamortized deferred financing costs related to the GoA Term Loan Facility as of June 30, 2026 and December 31, 2025, respectively.

Facility

The Facility supports our oil and gas exploration, appraisal and development programs and corporate activities. The amount of funds available to be borrowed under the Facility, also known as the borrowing base amount, is determined every March and September. In April 2026, during the Spring 2026 redetermination, the Company’s lending syndicate approved a borrowing base at approximately $1.25 billion. The borrowing base amount was based on the sum of the net present values of net cash flows and relevant capital expenditures reduced by certain percentages as well as value attributable to certain assets’ reserves and/or resources in the Company’s production assets in Ghana and Equatorial Guinea. Following the closing of the sale of all our participating interest in the Ceiba Field and Okume Complex production assets located in Block G offshore Equatorial Guinea on June 16, 2026, the Company’s production assets in Equatorial Guinea are no longer included in the borrowing base amount, and, as agreed with the lending syndicate, the borrowing base has been reduced to approximately $1.2 billion. As of June 30, 2026, borrowings under the Facility totaled approximately $0.8 billion and the undrawn availability under the Facility was approximately $440 million. Final maturity of the Facility is December 31, 2029.

Interest on the Facility is the aggregate of the applicable margin (4.00% to 5.50%, depending on the length of time that has passed from the date the Facility was entered into), plus the term SOFR reference rate administered by CME Group Benchmark Administration Limited for the relevant period published. Interest is payable on the last day of each interest period (and, if the interest period is longer thansix months, on the dates falling atsix-month intervals after the first day of the interest period). We pay commitment fees on the undrawn and unavailable portion of the total commitments, if any. Commitment fees are equal to 30% per annum of the then-applicable respective margin when a commitment is available for utilization and, equal to 20% per annum of the then-applicable respective margin when a commitment is not available for utilization. We recognize interest expense in accordance with ASC 835 — Interest, which requires interest expense to be recognized using the effective interest method. We determined the effective interest rate based on the estimated level of borrowings under the Facility.

The Facility provides a revolving credit and letter of credit facility. As of June 30, 2026, we hadno letters of credit issued under the Facility.

When our debt cover ratio exceeds 2.50 x, we are required under the Facility to maintain a restricted cash balance that is sufficient to meet the payment of interest and fees for the nextsix-month period on the 7.750% Senior Notes, the 7.500% Senior Notes, the 8.750% Senior Notes and the 3.125% Convertible Senior Notes or the Facility, whichever is greater. During the first quarter of 2025, the Facility lenders waived the requirement to maintain a restricted cash balance until the financial covenant test date to be calculated on March 31, 2026. During the second quarter of 2026, the Facility lenders agreed to reduce the amount of the required restricted cash balance to three months of interest and fees until the September 30, 2026 financial covenant test date, after which the amount of the required restricted cash balance will be determined as usual. Our debt cover ratio for the most recent March 31, 2026 financial covenant test date exceeded 2.50 x and the estimated restricted cash funding requirement is approximately $23.5 million. As of June 30, 2026 we have funded approximately $23.5 million into the debt service reserve account as required under the terms of the Facility.

In July 2025, the Company and the Facility lenders agreed to amend the debt cover ratio required under the Facility. The amendment made this covenant less restrictive for the followingtwo scheduled financial covenant assessment dates, up to a maximum of 4.0 x and 4.25 x, respectively, and thereafter returned to the originally agreed upon ratio of 3.50 x for assessment dates thereafter. In February 2026, we further amended the debt cover ratio calculation through September 2026. This most recent amendment makes the covenant less restrictive for the followingtwo scheduled financial covenant assessment dates, up to a maximum of 4.5 x and 4.25 x respectively, and for purposes of the financial covenant assessment date in March 2026, the calculation was made excluding the Company’s Mauritania and Senegal business unit. The debt cover ratio returns to the originally agreed upon ratio of 3.5 x for assessment dates thereafter.

We were in compliance with the financial covenants, as amended, contained in the Facility as of the most recent assessment date. The Facility contains customary cross default provisions.

7.125% Senior Notes due 2026

In April 2019, the Company issued $650.0 million of 7.125% Senior Notes and received net proceeds of approximately $640.0 million after deducting fees. The 7.125% Senior Notes mature on April 4, 2026.

On September 24, 2024, the Company completed the repurchase of an aggregate principal amount of $400.0 million of the 7.125% Senior Notes pursuant to the Company’s cash tender offers for portions of the 7.125% Senior Notes, the 7.750% Senior Notes, and the 7.500% Senior Notes announced on September 9, 2024 (the “Tender Offers”). In October 2025, we used proceeds from funding of the first tranche under the GoA Term Loan Facility to complete the partial redemption of an additional aggregate principal amount of $150.0 million of the 7.125% Senior Notes. In January 2026, we used the proceeds from funding the second tranche under the GoA Term Loan Facility, together with cash on hand, to complete the redemption of the remaining outstanding balance amount of $100.0 million of the 7.125% Senior Notes.

7.750% Senior Notes due 2027

In October 2021, the Company issued $400.0 million of 7.750% Senior Notes and received net proceeds of approximately $395.0 million after deducting fees. The 7.750% Senior Notes mature on May 1, 2027. Interest is payable in arrears each May 1 and November 1, commencing on May 1, 2022. The 7.750% Senior Notes are senior, unsecured obligations of Kosmos Energy Ltd. and rank equal in right of payment with all of its existing and future senior indebtedness (including all borrowings under the 7.500% Senior Notes, the 8.750% Senior Notes and the 3.125% Convertible Senior Notes) and rank effectively junior in right of payment to all of its existing and future secured indebtedness (including all borrowings under the Facility). The 7.750% Senior Notes are guaranteed on a senior, unsecured basis by certain subsidiaries owning the Company's Gulf of America assets, and on a subordinated, unsecured basis by certain subsidiaries that borrow under, or guarantee, the Facility and that guarantee the 7.500% Senior Notes, the 8.750% Senior Notes and the 3.125% Convertible Senior Notes.

On September 24, 2024, the Company completed the repurchase of an aggregate principal amount of $50.0 million of the 7.750% Senior Notes pursuant to the Tender Offers. In the first half of 2026, the Company used a portion of the net proceeds from the Nordic bond offering to fund the repurchase of an aggregate principal amount of $250.0 million of the 7.750% Senior Notes pursuant to the Company’s cash tender offer announced on January 12, 2026 and open market repurchases. The 7.750% Senior Notes contain customary cross default provisions.

7.500% Senior Notes due 2028

In March 2021, the Company issued $450.0 million of 7.500% Senior Notes and received net proceeds of approximately $444.4 million after deducting fees. The 7.500% Senior Notes mature on March 1, 2028. Interest is payable in arrears each March 1 and September 1, commencing on September 1, 2021. The 7.500% Senior Notes are senior, unsecured obligations of Kosmos Energy Ltd. and rank equal in right of payment with all of its existing and future senior indebtedness (including all borrowings under the 7.750% Senior Notes, the 8.750% Senior Notes and the 3.125% Convertible Senior Notes) and rank effectively junior in right of payment to all of its existing and future secured indebtedness (including all borrowings under the Facility). The 7.500% Senior Notes are guaranteed on a senior, unsecured basis by certain subsidiaries owning the Company's Gulf of America assets, and on a subordinated, unsecured basis by certain subsidiaries that borrow under, or guarantee, the Facility and that guarantee the 7.750% Senior Notes, the 8.750% Senior Notes and the 3.125% Convertible Senior Notes.

On September 24, 2024, the Company completed the repurchase of an aggregate principal amount of approximately $49.7 million of the 7.500% Senior Notes pursuant to the Tender Offers. The 7.500% Senior Notes contain customary cross default provisions.

8.750% Senior Notes due 2031

In September 2024, the Company issued $500.0 million of 8.750% Senior Notes (the “8.750% Senior Notes”) and received net proceeds of approximately $494.9 million after deducting fees. The 8.750% Senior Notes mature on October 1, 2031. Interest is payable in arrears each April 1 and October 1, commencing on April 1, 2025. The 8.750% Senior Notes are senior, unsecured obligations of Kosmos Energy Ltd. and rank equal in right of payment with all of its existing and future senior indebtedness (including all borrowings under the 7.750% Senior Notes, the 7.500% Senior Notes and the 3.125% Convertible Senior Notes) and rank effectively junior in right of payment to all of its existing and future secured indebtedness (including all borrowings under the Facility). The 8.750% Senior Notes are guaranteed on a senior, unsecured basis by certain subsidiaries owning the Company’s Gulf of America assets and on a subordinated, unsecured basis by certain subsidiaries that borrow under, or guarantee, the Facility and that guarantee the 7.750% Senior Notes, the 7.500% Senior Notes and the 3.125% Convertible Senior Notes. The 8.750% Senior Notes contain customary cross default provisions.

3.125% Convertible Senior Notes due 2030

In March 2024, the Company issued $400.0 million of 3.125% Convertible Senior Notes (the “3.125% Convertible Senior Notes”) and received net proceeds of $390.4 million after deducting fees. The 3.125% Convertible Senior Notes mature on March 15, 2030, unless earlier converted, redeemed or repurchased. Interest is payable in arrears each March 15 and September 15, commencing September 15, 2024. The 3.125% Convertible Senior Notes are senior, unsecured obligations of Kosmos Energy Ltd. and rank equal in right of payment with all of its existing and future senior indebtedness (including all borrowings under the 7.750% Senior Notes, the 7.500% Senior Notes and the 8.750% Senior Notes) and rank effectively junior in right of payment to all of its existing and future secured indebtedness (including all borrowings under the Facility, to the extent of the value of the assets securing such indebtedness). The 3.125% Convertible Senior Notes are guaranteed on a senior, unsecured basis by certain of our existing subsidiaries that guarantee on a senior basis the 7.750% Senior Notes, the 7.500% Senior Notes and the 8.750% Senior Notes, and, in certain circumstances, certain of our other existing or future subsidiaries. The 3.125% Convertible Senior Notes are guaranteed on a subordinated, unsecured basis by certain of our existing subsidiaries that borrow under or guarantee the Facility and guarantee on a subordinated basis the 7.750% Senior Notes, the 7.500% Senior Notes and the 8.750% Senior Notes, and, in certain circumstances, certain of our other existing or future subsidiaries.

The 3.125% Convertible Senior Notes indenture contains customary terms and covenants and cross default provisions.

The Company recorded the 3.125% Convertible Senior Notes, including the debt itself and all embedded derivatives, at cost less debt issuance costs of $9.6 million and has presented the 3.125% Convertible Senior Notes as a single financial instrument in Long-term debt, net in our consolidated balance sheet. No portion of the embedded derivatives required bifurcation from the host debt contract. As of June 30, 2026, the effective annual interest rate on the 3.125% Convertible Senior Notes is approximately 3.70%, including amortization of debt issuance costs.

The conversion rate for the 3.125% Convertible Senior Notes is initially 142.4501 shares of our common stock per $1,000 principal amount of 3.125% Convertible Senior Notes (which is the equivalent to an initial conversion price of approximately $7.02 per share of our common stock), subject to adjustments. As of June 30, 2026, no shares have been converted.

Capped Call Transactions

In connection with the issuance of the 3.125% Convertible Senior Notes, the Company used $49.8 million of the net proceeds from the issuance of the 3.125% Convertible Senior Notes to enter into capped call transactions (the “Capped Call Transactions”). The Capped Call Transactions are generally expected to reduce potential dilution to holders of our common stock upon any conversion of the 3.125% Convertible Senior Notes and/or offset any cash payments that we are required to make in excess of the principal amount of any 3.125% Convertible Senior Notes that are converted, as the case may be, with such reduction and/or offset subject to a cap.

The Capped Call Transactions qualify for a derivative scope exception as they are indexed to our common stock and are not required to be accounted for as a separate derivative. Consequently, the Capped Call Transactions have been included as a net reduction to additional-paid-in-capital within stockholders’ equity in our consolidated balance sheet and do not require subsequent remeasurement.

GoA Term Loan Facility

On September 24, 2025, the Company entered into a senior secured term loan credit agreement secured by first priority liens on all of the Company’s Gulf of America assets (as defined in the credit agreement). The GoA Term Loan Facility is structured intwo tranches, with the first tranche consisting of afour-year term loan in an aggregate principal amount of $150.0 million, which was funded on October 1, 2025 with net proceeds received of $147.2 million after deducting fees and other expenses, and a second tranche of an additional $100.0 million, which funded in January 2026 with net proceeds received of $98.5 million after deducting fees and expenses.

The net proceeds were used, together with cash on hand, to fund the redemption of $250.0 million in aggregate of the 7.125% Senior Notes due 2026. On March 24, 2026, we made a voluntary prepayment of $53.6 million against the GoA Term Loan. On May 1, 2026, the GoA Term Loan Facility was amended to apply this prepayment in full satisfaction of the scheduled principal amount due on the first scheduled amortization payment date on June 30, 2026, and then ratably to all remaining scheduled principal payments of the outstanding loans. The amendment also deferred all future scheduled amortization payment dates in 2026, 2027 and 2028 such that they will now be due on October 1, January 1, April 1 and July 1 in each of 2026, 2027 and 2028. As a result of the amendment, there is only one remaining scheduled amortization payment in 2026 to be paid on October 1, 2026.

Interest on outstanding loans under the GoA Term Loan Facility is payable quarterly in arrears at a rate per annum equal to 3.75% plus the term SOFR reference rate administered by CME Group Benchmark Administration Limited for the relevant period published. The GoA Term Loan Facility matures in 2029.

The GoA Term Loan Facility contains customary affirmative and negative covenants, including covenants that affect our ability to incur additional indebtedness, create liens, merge, dispose of assets, and make distributions, dividends, investments or capital expenditures, among other things. The GoA Term Loan Facility requires the Company to maintain certain financial covenants including:

•the GoA field life coverage ratio (as defined in the glossary), not less than 1.50 x; and

•the GoA net leverage ratio (as defined in the glossary), not more than 3.50 x.

The GoA Term Loan Facility also includes certain representations and warranties, indemnities and events of default that, subject to materiality thresholds and grace periods, arise as a result of a payment of default, failure to comply with covenants, material inaccuracy of representation or warranty, and certain bankruptcy or insolvency proceedings. If there is an event of default, all or any portion of the outstanding indebtedness may be immediately due and payable and other rights may be exercised including against the collateral. We were in compliance with the covenants, representations and warranties contained in the GoA Term Loan Facility as of the most recent assessment date.

GTA Nordic bonds

In January 2026 the Company issued $350.0 million of 11.250% senior secured bonds due 2031 in the Nordic market (the “GTA Nordic bonds”). In the first quarter of 2026, the Company used the net proceeds from the Nordic bond offering to fund the repurchase of an aggregate principal amount of $249.8 million of the 7.750% Senior Notes pursuant to the Company’s cash tender offer announced on January 12, 2026 and open market repurchases, and to make a voluntary early principal repayment of $100.0 million on outstanding borrowings under the Facility.

The GTA Nordic bonds mature in January 2031. Interest is payable semi-annually in arrears each July 29 and January 29, commencing on July 29, 2026. The GTA Nordic bonds were issued by Kosmos Energy GTA Holdings, a wholly-owned subsidiary of Kosmos Energy Ltd., and are fully and unconditionally guaranteed by the Company and the Company’s wholly-owned subsidiaries, Kosmos Energy Tortue Finance, Kosmos Energy Senegal, Kosmos Energy Investments Senegal Limited and Kosmos Energy Mauritania. The GTA Nordic bonds are also guaranteed on an unsecured basis by certain of the Company’s subsidiaries that also guarantee the Company’s existing senior unsecured notes.

At any time prior to July 29, 2028, the Company may, on any one or more occasions, redeem all or part of the GTA Nordic bonds at a redemption price equal to 100%, plus any accrued and unpaid interest, and plus a “make-whole” premium. On and after July 29, 2028, the Company may redeem all or part of the GTA Nordic bonds at the following redemption prices (expressed as a percentage of principal amount), plus accrued and unpaid interest, if any, on the notes redeemed:

If the Company’s shares are no longer listed on the New York Stock Exchange or upon the occurrence of a change of control event, as defined in the Bond Terms for the GTA Nordic bonds, each Nordic bondholder shall have a right to require that the Company repurchase all or some of the GTA Nordic bonds held by that Nordic bondholder (a “Put Option”) at a repurchase price equal to 101% of the principal amount, plus accrued and unpaid interest to, but excluding, the date of repurchase. If more than 90% of the outstanding GTA Nordic bonds have been repurchased as a result of the exercise of the Put Option, the Company will be entitled to repurchase all the remaining GTA Nordic bonds at a price equal to 101% of the principal amount.

The Bond Terms governing the GTA Nordic bonds restrict the ability of Kosmos Energy GTA Holdings, Kosmos Energy Tortue Finance, Kosmos Energy Senegal, Kosmos Energy Investments Senegal Limited and Kosmos Energy Mauritania to, among other things: incur or guarantee additional indebtedness, create liens, sell assets, enter into transactions with affiliates, or effect certain consolidations, mergers or amalgamations.

The Bond Terms governing the GTA Nordic bonds also require Kosmos Energy GTA Holdings to maintain certain financial covenants including:

•Minimum Liquidity (as defined in the Bond Terms) of not less than $17.5 million or 5% of the outstanding GTA Nordic bonds, whichever is greater; and

•an Asset Coverage Ratio (as defined in the Bond Terms) of at least 1.25 x

We were in compliance with the financial covenants as of the most recent assessment date. The GTA Nordic bonds contains customary cross default provisions.

Principal Debt Repayments

At June 30, 2026, the estimated repayments of debt during the five fiscal year periods and thereafter are as follows:

(1)Includes the scheduled maturities for outstanding principal debt balances. The scheduled maturities of debt related to the Facility as of June 30, 2026 are based on our level of borrowings and our estimated future available borrowing base commitment levels in future periods. Any increases or decreases in the level of borrowings or increases or decreases in the available borrowing base would impact the scheduled maturities of debt during the next five years and thereafter.

(2)Represents payments for the period July 1, 2026 through December 31, 2026.

Interest and other financing costs, net

Interest and other financing costs, net incurred during the periods is comprised of the following:

9. Derivative Financial Instruments

We use financial derivative contracts to manage exposures to commodity price and interest rate fluctuations. We do not hold or issue derivative financial instruments for trading purposes.

We manage market and counterparty credit risk in accordance with our policies and guidelines. In accordance with these policies and guidelines, our management determines the appropriate timing and extent of derivative transactions. We have included an estimate of non-performance risk in the fair value measurement of our derivative contracts as required by ASC 820 — Fair Value Measurement.

Oil Derivative Contracts

The following table sets forth the volumes in barrels underlying the Company’s outstanding oil derivative contracts and the weighted average prices per Bbl for those contracts as of June 30, 2026. Volumes and weighted average prices are net of any offsetting derivative contracts entered into.

(1)Includes option contracts sold to counterparties to enhance Swaps.

In July 2026, we entered into Dated Brent two-way collar contracts for 2.0 MMBbl from January 2027 through December 2027 with a weighted average floor price of $67.50 per barrel and a ceiling price of $90.00 per barrel.

The following tables disclose the Company’s derivative instruments as of June 30, 2026 and December 31, 2025, and gain/(loss) from derivatives during the three and six months ended June 30, 2026 and 2025, respectively:

Offsetting of Derivative Assets and Derivative Liabilities

Our derivative instruments which are subject to master netting arrangements with our counterparties only have the right of offset when there is an event of default. As of June 30, 2026 and December 31, 2025, there was not an event of default and, therefore, the associated gross asset or gross liability amounts related to these arrangements are presented on the consolidated balance sheets.

10. Fair Value Measurements

In accordance with ASC 820 — Fair Value Measurement, fair value measurements are based upon inputs that market participants use in pricing an asset or liability, which are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources, whereas unobservable inputs reflect a company’s own market assumptions, which are used if observable inputs are not reasonably available without undue cost and effort. We prioritize the inputs used in measuring fair value into the following fair value hierarchy:

•Level 1 — quoted prices for identical assets or liabilities in active markets.

•Level 2 — quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs derived principally from or corroborated by observable market data by correlation or other means.

•Level 3 — unobservable inputs for the asset or liability. The fair value input hierarchy level to which an asset or liability measurement in its entirety falls is determined based on the lowest level input that is significant to the measurement in its entirety.

The following tables present the Company’s assets and liabilities that are measured at fair value on a recurring basis as of June 30, 2026 and December 31, 2025, for each fair value hierarchy level:

The book values of cash and cash equivalents and restricted cash approximate fair value based on Level 1 inputs. Joint interest billings, oil and gas sales and other receivables, and accounts payable and accrued liabilities approximate fair value due to the short-term nature of these instruments. Our long-term receivables, after any allowances for credit losses, and other long-term assets approximate fair value. The estimates of fair value of these items are based on Level 2 inputs.

Commodity Derivatives

Our commodity derivatives represent swaps, crude oil collars, put options and call options for notional barrels of oil at fixed Dated Brent and NYMEX WTI oil prices. The values attributable to our oil derivatives are based on (i) the contracted notional volumes, (ii) independent active futures price quotes for the respective index, (iii) a credit-adjusted yield curve applicable to each counterparty by reference to the credit default swap (“CDS”) market and (iv) an independently sourced estimate of volatility for the respective index. The volatility estimate was provided by certain independent brokers who are active in buying and selling oil options and was corroborated by market-quoted volatility factors. The deferred premium is included in the fair market value of the commodity derivatives. See Note 9 — Derivative Financial Instruments for additional information regarding the Company’s derivative instruments.

Provisional Sales Contracts

The value attributable to provisional sales contracts derivative is based on (i) the sales volumes and (ii) the difference in the independent active futures price quotes for the respective index over the term of the pricing period designated in the sales contract and the spot price on the date of sale.

Decommissioning Trust Fund

In April 2024, a decommissioning trust agreement with the Jubilee unit partners to cash fund future retirement costs associated with the Jubilee Field was finalized. Each partner contributes annually to the trust in proportion to its respective paying interest of the estimated future dismantlement, abandonment and restoration costs associated with the decommissioning of the Jubilee Field. Contributions to the trust are used by the trustee of the fund, the Bank of Ghana, to purchase and sell authorized securities at the direction of the Jubilee unit partners.

As of June 30, 2026, the investments held in the decommissioning trust fund are US Treasury debt securities. We have classified the investments as trading securities and recorded such investments at fair market value as a long-term investment in our consolidated balance sheet using observable inputs including Kosmos’ share of the fund and broker/dealer bid/ask prices of the investments held by the fund at June 30, 2026. Contributions made to the decommissioning trust are reported as investing activities in our consolidated cash flows. All realized and unrealized gains and losses resulting from the sales and maturities or changes in fair value of the securities are recognized in Other income, net. During the six months ended June 30, 2026 and 2025, we contributed $11.6 million and $11.5 million to the decommissioning trust fund, respectively.

The following table summarizes the cost and fair value, purchases, proceeds from the sale and maturities, and the unrealized gains (losses) for Kosmos’ portion of the investments in debt securities held by the decommissioning trust during the six months ended June 30, 2026 and 2025:

(1) Represents net receivables relating to interest.

The following table presents the costs and fair values of investments in debt securities held in the decommissioning trust fund according to the contractual maturities at June 30, 2026 and December 31, 2025:

Debt

The following table presents the carrying values and fair values at June 30, 2026 and December 31, 2025:

The carrying values of our 7.125% Senior Notes,7.750% Senior Notes,7.500% Senior Notes,8.750% Senior Notes and 3.125% Convertible Senior Notes represent the principal amounts outstanding less unamortized discounts. The fair values of our 7.125% Senior Notes,7.750% Senior Notes,7.500% Senior Notes,8.750% Senior Notes,3.125% Convertible Senior Notes and 11.250% Senior Secured Bonds are based on quoted market prices, which results in a Level 1 fair value measurement. The carrying value of the GoA Term Loan Facility and Facility approximates fair value since they are subject to short-term floating interest rates that approximate the rates available to us for those periods.

Nonrecurring Fair Value Measurements - Long-lived assets

Certain long-lived assets are reported at fair value on a non-recurring basis on the Company's consolidated balance sheet. These long-lived assets are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances. Our long-lived assets are reviewed for impairment when changes in circumstances indicate that the carrying amount of an asset may not be recoverable.

The Company calculates the estimated fair values of its long-lived assets using the income approach described in the ASC 820 — Fair Value Measurements. Significant inputs associated with the calculation of estimated discounted future net cash flows include anticipated future production, pricing estimates, capital and operating costs, market-based weighted average cost of capital, and risk adjustment factors applied to reserves. These are classified as Level 3 fair value assumptions. The Company utilizes an average of third-party industry forecasts of Dated Brent, adjusted for location and quality differentials, to determine our pricing assumptions. In order to evaluate the sensitivity of the assumptions, we analyze sensitivities to prices, production, and risk adjustment factors.

During the three and six months ended June 30, 2026 and 2025, the Company didnot recognize impairment of proved oil and gas properties. If we experience material declines in oil pricing expectations in the future, significant increases in our estimated future expenditures or a significant decrease in our estimated production profile, our long-lived assets could be at risk of impairment.

11. Equity-based Compensation

Restricted Stock Units

We record equity-based compensation expense equal to the fair value of share-based payments over the vesting periods of the LTIP awards. We recorded compensation expense from awards granted under our LTIP of $8.1 million and $7.3 million during the three months ended June 30, 2026 and 2025, respectively, and $14.1 million and $15.7 million during the six months ended June 30, 2026 and 2025, respectively. The total tax benefit for the three months ended June 30, 2026 and 2025 was $0.9 million and $1.2 million, respectively, and $1.9 million and $2.6 million during the six months ended June 30, 2026 and 2025, respectively. Additionally, we recorded a net tax shortfall (windfall) related to equity-based compensation of $(0.1) million and $0.3 million for the three months ended June 30, 2026 and 2025, respectively, and $7.6 million and $3.4 million during the six months ended June 30, 2026 and 2025, respectively. The fair value of awards vested during the three months ended June 30, 2026 and 2025 was $2.0 million and $0.6 million, respectively, and $5.7 million and $19.7 million during the six months ended June 30, 2026 and 2025, respectively. The Company granted restricted stock units with service vesting criteria and a combination of market and service vesting criteria under the LTIP. Substantially all of these grants vest over three years. Upon vesting, restricted stock units become issued and outstanding stock.

For restricted stock units with a combination of market and service vesting criteria, the number of common shares to be issued is determined by comparing the Company’s total shareholder return with the total shareholder return of a predetermined group of peer companies over the performance period and can vest in up to 200% of the awards granted. The grant date fair value ranged from $1.94 to $13.06 per award. The Monte Carlo simulation model utilized multiple input variables that determined the probability of satisfying the market condition stipulated in the award grant and calculated the fair value of the award. The expected volatility utilized in the model was estimated using our historical volatility and the historical volatilities of our peer companies and ranged from 58.0% to 105.0%. The risk-free interest rate was based on the U.S. treasury rate for a term commensurate with the expected life of the grant and ranged from 1.3% to 4.2%.

The following table reflects the outstanding restricted stock units as of June 30, 2026:

(1)The restricted stock units with a combination of market and service vesting criteria may vest between 0% and 200% of the originally granted units depending upon market performance conditions. Awards vesting over or under target shares of 100% results in additional shares granted or forfeited, respectively, in the period the market vesting criteria is determined.

As of June 30, 2026, total equity-based compensation to be recognized on unvested restricted stock units is $21.2 million over a weighted average period of 1.74 years. At June 30, 2026, the Company had approximately 11.9 million shares that remain available for issuance under the LTIP.

12. Income Taxes

We evaluate our estimated annual effective income tax rate each quarter, based on current and forecasted business results and enacted tax laws, and apply this tax rate to our ordinary income or loss to calculate our estimated tax expense or benefit. The Company excludes zero statutory tax rate and tax-exempt jurisdictions from our evaluation of the estimated annual effective income tax rate. The tax effect of discrete items are recognized in the period in which they occur at the applicable statutory tax rate.

Income (loss) before income taxes is composed of the following:

(1)Foreign tax expense includes amounts related to Ceiba and Okume Complex located in Block G offshore Equatorial Guinea through the date of sale in June 2026. See Note 3 - Acquisitions and Divestitures for additional information.

For the three months ended March 31, 2026 and 2025, our effective tax rate was 35% and (38)%, respectively. For the six months ended June 30, 2026 and 2025, our effective tax rate was 199% and (26)%, respectively. For the three and six months ended June 30, 2026 and 2025, our overall effective tax rate was impacted by:

•The difference in our 21% U.S. income tax reporting rate and the statutory income tax rates applicable to our foreign operations, primarily in Ghana.

•Jurisdictions that have a 0% statutory tax rate or that are exempt,

•Jurisdictions where we have incurred losses and have recorded valuation allowances against the corresponding deferred tax assets, and

•Other non-deductible expenses

13. Net Income (Loss) Per Share

The following table is a reconciliation between net income (loss) and the amounts used to compute basic and diluted net income (loss) per share and the weighted average shares outstanding used to compute basic and diluted net income (loss) per share. Potentially dilutive securities include shares issuable upon conversion of our 3.125% Convertible Senior Notes using the if-converted method and restricted stock units awards under our equity-based compensation plan.

(1)We excluded restricted stock units of 2.5 million and 5.2 million for the three months ended June 30, 2026 and 2025, respectively, and 17.1 million and 5.9 million for the six months ended June 30, 2026 and 2025, respectively from the computations of diluted net income (loss) per share because the effect would have been anti-dilutive.

(2)Represents the dilutive impact for the Company’s 3.125% Convertible Senior Notes due 2030. As of June 30, 2026, the if-converted value is less than the outstanding principal of the 3.125% Convertible Senior Notes and therefore anti-dilutive. The 3.125% Convertible Senior Notes are subject to a capped call arrangement that potentially reduces the dilutive effect. Any potential impact of the capped call arrangement is excluded from this table as any proceeds under the capped call arrangement are considered anti-dilutive.

On March 10, 2026 the Company launched and priced a registered underwritten public offering of 112.1 million shares of common stock, par value $0.01, resulting in net proceeds to Kosmos of approximately $206.4 million. The offering closed on March 12, 2026.

14. Commitments and Contingencies

From time to time, we are involved in litigation, regulatory examinations and administrative proceedings primarily arising in the ordinary course of our business in jurisdictions in which we do business. Although the outcome of these matters cannot be predicted with certainty, management believes that the likelihood of an unfavorable outcome having a material impact is neither reasonably possible nor probable of occurring.

As of June 30, 2026, we have a commitment to drill a minimum often development wells under the amended Jubilee plan of development as part of the license extensions of WCTP and DT Petroleum Agreements in Ghana.

In April 2024, a decommissioning trust agreement with the Jubilee unit partners to cash fund future retirement costs associated with the Jubilee Field was finalized. The operator currently estimates the total remaining commitment to be approximately $111.0 million as of June 30, 2026, net to Kosmos, which will be funded annually by Kosmos over an estimated fourteen year period.

Performance Obligations

As of June 30, 2026 and December 31, 2025, the Company had performance and supplemental bonds totaling $150.5 million and $151.6 million, respectively, related to bonding requirements stipulated by the BOEM and other third parties for anticipated plugging and abandonment costs of certain wells and the removal of certain facilities in our Gulf of America fields.

Once the Tortue Phase 1 SPA Commercial Operations Date was achieved in February 2026, we have a commitment to our buyer under the Tortue Phase 1 SPA, BP Gas Marketing Limited, to deliver our proportionate share of a minimum annual contract quantity of LNG of 127,951,000 MMBtu, which is equivalent to approximately 2.45 million tonnes per annum, subject to certain downward adjustments by the sellers. Under certain circumstances, in the event the annual quantities provided are lower than the minimum annual contract quantity, Kosmos may be obligated to credit or pay a portion of the Contract Price to BP Gas Marketing Limited for the shortfall volumes.

In February 2026, Tullow, as Operator of the TEN partnership, executed the final Sale and Purchase Agreement enabling the partnership to acquire the TEN FPSO from MODEC, Inc. at the end of its current lease in 2027 for a gross purchase price of $205.0 million. We have a commitment to Tullow for our proportionate share of the gross purchase price.

15. Additional Financial Information

Accrued Liabilities

Accrued liabilities consisted of the following:

Asset Retirement Obligations

The following table summarizes the changes in the Company's asset retirement obligations as of and during the six months ended June 30, 2026:

The liabilities settled during 2026 primarily relate to the sale of the Ceiba and Okume Complex production assets located in Block G offshore Equatorial Guinea in June 2026. See Note 3 - Acquisitions and Divestitures.

16. Business Segment Information

Kosmos is engaged in a single line of business, which is the exploration, development and production of oil and gas. For the three and six months ended June 30, 2026, the Company’s segment information is presented forfour geographic reporting segments: Ghana, Equatorial Guinea, Mauritania/Senegal and the Gulf of America. The Equatorial Guinea segment reflects the results of the Ceiba Field and Okume Complex production assets located in Block G offshore Equatorial Guinea through the date of sale in June 2026. See Note 3 - Acquisitions and Divestitures for additional information. The Company’s Chief Operating Decision Maker (“CODM”) is the Chief Executive Officer, who makes decisions about allocating resources and assessing performance for the entire company. To assess performance of the reporting segments, the CODM regularly reviews oil and gas revenues, oil and gas production costs, exploration expenses and capital expenditures by reporting segment in deciding how to allocate resources and in assessing performance. Capital expenditures, as defined by the Company, may not be comparable to similarly titled measures used by other companies and should be considered in conjunction with our consolidated financial statements and notes thereto. Financial information for each area is presented below:

(1)Interest expense is recorded based on actual third-party and intercompany debt agreements. Capitalized interest is recorded on the business unit where the assets reside.

(2)In June 2026, the Company completed the disposition of its interests in the Ceiba Field and Okume Complex production assets located in Block G offshore Equatorial Guinea. The operating results of the Equatorial Guinea segment are included in the Company's consolidated results through the date of sale in June 2026. The disposition did not qualify for discontinued operations presentation. See Note 3 - Acquisitions and Divestitures for additional information.

(1)Interest expense is recorded based on actual third-party and intercompany debt agreements. Capitalized interest is recorded on the business unit where the assets reside.

(2)In June 2026, the Company completed the disposition of its interests in the Ceiba Field and Okume Complex production assets located in Block G offshore Equatorial Guinea. The disposition did not qualify for discontinued operations presentation. See Note 3 - Acquisitions and Divestitures for additional information.

(1)Costs related to unsuccessful exploratory wells and leaseholds that are subsequently written off to Exploration expense are included in oil and gas assets when incurred.