MUELLER INDUSTRIES INC

CONDENSED CONSOLIDATED STATEMENTS OF INCOME

(1)Adjusted retroactively to reflect thetwo-for-one stock split that occurred on June 30, 2026. Refer to Note 2 - Earnings per Common Share for additional information.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

CONDENSED CONSOLIDATED BALANCE SHEETS

(1) Adjusted retroactively to reflect thetwo-for-one stock split that occurred on June 30, 2026. Refer to Note 2 - Earnings per Common Share for additional information.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

General

Certain information and note disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) have been condensed or omitted. Results of operations for the interim periods presented are not necessarily indicative of results which may be expected for any other interim period or for the year as a whole. This Quarterly Report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K, including the annual financial statements incorporated therein.

The accompanying unaudited interim financial statements include all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the results for the interim periods presented herein. Certain prior year balances have been reclassified to conform to current year presentation.

Note 1 –Recently Issued Accounting Standards

In December 2025, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2025-12, Codification Improvements. The new guidance addresses suggestions received from stakeholders regarding the Accounting Standards Codification (ASC) and makes other incremental improvements to U.S. GAAP. The update represents changes to the ASC that clarify, correct errors in, or make other improvements to a variety of topics that are intended to make it easier to understand and apply. The ASU is effective for fiscal years beginning after December 15, 2026 and interim periods within those fiscal years. Entities are required to apply the amendments to ASC 260 retrospectively. All other amendments may be applied prospectively or retrospectively. Early adoption is permitted. The Company is evaluating the impact of this guidance on its Condensed Consolidated Financial Statements and related disclosures.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements. The new guidance is intended to improve the navigability of guidance in ASC 270, Interim Reporting, and clarify when it applies. The amendments also provide guidance on what disclosures should be provided in interim reporting periods. The ASU is effective for interim reporting periods within annual reporting periods beginning after December 15, 2027. The guidance can be applied prospectively or retrospectively, and early adoption is permitted. The Company is in the process of analyzing the impact of the standard on its disclosures.

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 new guidance requires disclosure of additional information about specific expense categories. The guidance applies to all public entities and is effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027. The updated guidance requires prospective adoption but may be applied retrospectively, and early adoption is permitted. The Company is in the process of analyzing the impact of the standard on its disclosures.

Note 2 –Earnings per Common Share

Basic earnings per share is computed based on the weighted average number of common shares outstanding. Diluted earnings per share reflects the increase in weighted average common shares outstanding that would result from the assumed exercise of outstanding stock options and vesting of restricted and performance stock awards calculated using the treasury stock method. There were 220 thousand and 153 thousand stock-based awards excluded from the computation of diluted earnings per share for the quarters ended September 26, 2026 and September 27, 2025, respectively, because they were antidilutive.

On May 29, 2026, the Company’s Board of Directors approved an amendment to the Company’s Restated Certificate of Incorporation to increase the total number of authorized shares of Common Stock from 250,000,000 to 500,000,000. Subsequently, the Company announced atwo-for-one stock split of its common stock effected in the form of a stock dividend ofone share for each outstanding share. The record date for the stock split was June 25, 2026, and the additional shares were distributed on June 30, 2026. Shares authorized in prior periods are not adjusted. All other references to share and per share amounts presented in the Condensed Consolidated Financial Statements and this Quarterly Report on Form 10-Q have been adjusted retroactively to reflect the stock split.

Note 3 –Acquisitions and Dispositions

Acquisitions

Bison Metals Technologies LLC

On March 30, 2026, the Company entered into a definitive agreement to acquire Bison Metals Technologies LLC (Bison) for approximately $135.8 million in cash, as well as $3.8 million of net debt assumed in the transaction, net of cash acquired and working capital adjustments. Bison is a U.S. manufacturer of copper tubes in Shawnee, Oklahoma for the industrial, technical, HVAC, plumbing and refrigeration markets. The acquisition complements and expands the Company’s existing businesses within the Piping Systems segment where the operating results are included in the Domestic Piping Systems Group subsequent to the acquisition date.

The purchase price is allocated to tangible and intangible assets acquired and liabilities assumed based on respective fair values at the acquisition date. The allocation, including the residual amount allocated to goodwill, is based on preliminary information and is subject to change as additional information concerning final asset and liability valuations are obtained and management completes its assessment of the valuations during the measurement period. Changes to the purchase price allocation from the amounts presented in the Company’s Quarterly Report on Form 10-Q for the quarter ended June 27, 2026 primarily included the final settlement of the closing statement and the valuation of inventory, property, plant, and equipment, and intangible assets. These changes resulted in a net decrease to goodwill of $104.9 million, and the impact of these measurement period adjustments to depreciation and amortization was not material to the Condensed Consolidated Statement of Income.

The provisional purchase price allocation is as follows:

In determining the fair value of amounts above, the Company utilized various forms of the income, cost, and market approaches depending on the asset or liability being valued. The estimation of fair value required judgment related to future net cash flows, discount rates, customer attrition rates, competitive trends, market comparisons, and other factors. As a result, the Company utilized third-party valuation specialists to assist in determining the fair value of certain assets. Inputs were generally determined by taking into account independent appraisals and historical data, supplemented by current and anticipated market conditions. Management believes that the purchase price attributable to goodwill represents future expected economic benefits, including enhanced revenue growth and operational efficiencies.

The acquisition of Bison was not material to the Company's financial position or results of operations; therefore, pro forma operating results and other disclosures related to the acquisition are not presented as the results would not be significantly different than the reported results.

Chicago Extruded Metals

On June 12, 2026, the Company acquired certain assets formerly owned by Chicago Extruded Metals for approximately $3.9 million in cash on hand.

Disposition

Sherwood Valve LLC

On December 17, 2025, the Company entered into a purchase agreement with CD OpCo Holdings, LLC pursuant to which the Company sold all of the outstanding membership interests of Sherwood Valve LLC (Sherwood) for approximately $57.0 million, net of working capital adjustments. The transaction closed on January 7, 2026. This business manufactures brass, aluminum, and stainless steel valves and fluid control solutions for the compressed gas and specialty markets in the U.S. It was included in the Industrial Metals segment. The business reported net sales of $10.5 million and operating income of $1.8 million during the third quarter of 2025, and net sales of $31.1 million and operating income of $5.4 million during the first nine months of 2025. The carrying value of the assets disposed totaled $17.7 million, consisting primarily of accounts receivable, inventories, and long-lived assets. The carrying value of the liabilities disposed totaled $2.1 million, consisting primarily of accounts payable and accrued payroll. As a result of the transaction, the Company recognized a pre-tax gain of $41.4 million on the sale of the business in the Condensed Consolidated Financial Statements during the first quarter of 2026.

Note 4 –Segment Information

Each of the Company’s reportable segments is composed of certain operating segments that are aggregated primarily by the nature of products offered as follows:

Piping Systems

Piping Systems is composed of the following operating segments: Domestic Piping Systems Group, Great Lakes Copper, European Operations, Trading Group, Jungwoo-Mueller (the Company’s South Korean joint venture), and Mueller Middle East (the Company’s Bahraini joint venture). The Domestic Piping Systems Group manufactures and distributes copper tube, fittings, and line sets. These products are manufactured in the U.S., sold in the U.S., and exported to markets worldwide. Outside the U.S., Great Lakes Copper manufactures copper tube and line sets in Canada and sells the products primarily in Canada. European Operations manufactures copper tube in the U.K. which is sold primarily in Europe. The Trading Group manufactures pipe nipples and resells brass and plastic plumbing valves, malleable iron fittings, faucets, and plumbing specialty products in the U.S. and Mexico. Jungwoo-Mueller manufactures copper-based joining products that are sold worldwide. Mueller Middle East manufactures copper tube and serves markets in the Middle East and Northern Africa. The Piping Systems segment’s products are sold primarily to plumbing, refrigeration, and air-conditioning wholesalers, hardware wholesalers and co-ops, building product retailers, and air-conditioning original equipment manufacturers (OEMs).

Industrial Metals

Industrial Metals is composed of the following operating segments: Brass Rod, Impacts & Micro Gauge, Brass Value-Added Products, Precision Tube, and Electrical Group. These businesses manufacture brass rod, impact extrusions, forgings, specialty copper, copper alloy, and aluminum tube, as well as a wide variety of end products including plumbing brass, automotive components, and high-quality wire and cable solutions. These products are manufactured in the U.S. and sold primarily to OEMs and utilities in the U.S., many of which are in the industrial, transportation, construction, heating, ventilation, and air-conditioning, plumbing, refrigeration, energy, telecommunication, and electrical transmission and distribution markets.

As disclosed in “Note 3 – Acquisitions and Dispositions,” during the first quarter of 2026 the Company sold the outstanding membership interests of Sherwood and recognized a $41.4 million gain. The gain is reported within Corporate and Eliminations. The results of Sherwood, prior to the sale, were included within the Industrial Metals segment.

Climate

Climate is composed of the following operating segments: Refrigeration Products, Westermeyer, Turbotec, Flex Duct, and Linesets, Inc. The segment manufactures and sells refrigeration valves and fittings, high pressure components, coaxial heat exchangers, insulated HVAC flexible duct systems, and line sets primarily for the heating, ventilation, air-conditioning, and refrigeration markets in the U.S.

The Company’s chief operating decision maker (CODM) is the chief executive officer. Performance of segments is generally evaluated by their operating income. Summarized product line and segment information is shown in the following tables. Unallocated expenses include general corporate expenses, plus certain charges or credits not included in segment activity.

The following tables represent a disaggregation of revenue from contracts with customers, along with the reportable segment for each category:

Disaggregation of revenue from contracts with customers (continued):

Summarized segment information is as follows:

Other segment disclosures:

Other segment disclosures (continued):

Note 5 –Cash, Cash Equivalents, and Restricted Cash

Amounts included in restricted cash relate to required deposits in brokerage accounts that facilitate the Company’s hedging activities as well as imprest funds for the Company’s self-insured workers’ compensation program.

Note 6 –Inventories

Inventories valued using the LIFO method totaled $36.3 million at September 26, 2026 and $7.5 million at December 27, 2025. At September 26, 2026 and December 27, 2025, the approximate FIFO cost of such inventories was $213.8 million and $147.2 million, respectively.

Note 7 –Financial Instruments

Short-Term Investments

The fair value of short-term investments at September 26, 2026 and December 27, 2025, consisting of marketable securities, approximates the carrying value on that date. These marketable securities are stated at fair value and classified as level 1 within the fair value hierarchy. This classification is defined as a fair value determined using observable inputs that reflect quoted prices in active markets for identical assets.

Derivative Instruments and Hedging Activities

The Company’s earnings and cash flows are subject to fluctuations due to changes in commodity prices, foreign currency exchange rates, and interest rates. The Company uses derivative instruments such as commodity futures contracts, foreign currency forward contracts, and interest rate swaps to manage these exposures.

All derivatives are recognized in the Condensed Consolidated Balance Sheets at their fair values. On the date the derivative contract is entered into, it is either a) designated as a hedge of a forecasted transaction or the variability of cash flow to be paid (cash flow hedge) or b) not designated in a hedge accounting relationship, even though the derivative contract was executed to mitigate an economic exposure (economic hedge), as the Company does not enter into derivative contracts for trading purposes. Changes in the fair value of a derivative that is qualified, designated, and highly effective as a cash flow hedge are recorded in stockholders’ equity within AOCI, to the extent effective, until they are reclassified to earnings in the same period or periods during which the hedged transaction affects earnings. Changes in the fair value of undesignated derivatives executed as economic hedges are reported in current earnings.

The Company documents all relationships between derivative instruments and hedged items, as well as the risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivative instruments that are designated as fair value hedges to specific assets and liabilities in the Condensed Consolidated Balance Sheets and linking cash flow hedges to specific forecasted transactions or variability of cash flow.

The Company also assesses, both at the hedge’s inception and on an ongoing basis, whether the designated derivative instruments that are used in hedging transactions are highly effective in offsetting changes in cash flows or fair values of hedged items. When a derivative instrument is determined not to be highly effective as a hedge or the underlying hedged transaction is no longer probable of occurring, hedge accounting is discontinued prospectively in accordance with the derecognition criteria for hedge accounting.

Commodity Futures Contracts

Copper and brass represent the largest component of the Company’s variable costs of production. The cost of these materials is subject to global market fluctuations caused by factors beyond the Company’s control. The Company occasionally enters into forward fixed-price arrangements with certain customers; the risk of these arrangements is generally managed with commodity futures contracts. These futures contracts have been designated as cash flow hedges.

At September 26, 2026, the Company held open futures contracts to purchase approximately $33.9 million of copper over the next 10 months related to fixed price sales orders. The fair value of those futures contracts was a $2.4 million net gain position, which was determined by obtaining quoted market prices (level 1 within the fair value hierarchy). In the next 12 months, the Company will reclassify into earnings realized gains or losses relating to cash flow hedges. At September 26, 2026, this amount was approximately $1.9 million of deferred net gains, net of tax.

The Company may also enter into futures contracts to protect the value of inventory against market fluctuations. At September 26, 2026, the Company held $67.5 million of open futures contracts to sell copper over the next six months related to copper inventory. The fair value of those futures contracts was a $1.5 million net loss position, which was determined by obtaining quoted market prices (level 1 within the fair value hierarchy).

The Company presents its derivative assets and liabilities in the Condensed Consolidated Balance Sheets on a net basis by counterparty. The following table summarizes the location and fair value of the derivative instruments and disaggregates the net derivative assets and liabilities into gross components on a contract-by-contract basis:

(1) Does not include the impact of cash collateral provided to counterparties.

The following table summarizes the effects of derivative instruments on the Company’s Condensed Consolidated Statements of Income:

The following tables summarize amounts recognized in and reclassified from AOCI during the period:

The Company primarily enters into International Swaps and Derivatives Association master netting agreements with major financial institutions that permit the net settlement of amounts owed under their respective derivative contracts. Under these master netting agreements, net settlement generally permits the Company or the counterparty to determine the net amount payable for contracts due on the same date and in the same currency for similar types of derivative transactions. The master netting agreements generally also provide for net settlement of all outstanding contracts with a counterparty in the case of an event of default or a termination event. The Company does not offset fair value amounts for derivative instruments and fair value amounts recognized for the right to reclaim cash collateral. At September 26, 2026 and December 27, 2025, the Company had recorded restricted cash in other current assets of $1.9 million and $17.9 million, respectively, as collateral related to open derivative contracts under the master netting arrangements.

Note 8 –Investments in Unconsolidated Affiliates

Tecumseh

The Company owns a 50 percent interest in an unconsolidated affiliate that acquired Tecumseh Products Company LLC (Tecumseh) and an entity that provides financing to Tecumseh. This investment is recorded using the equity method of accounting, as the Company can exercise significant influence but does not own a majority equity interest or otherwise control the entity. Under the equity method of accounting, this investment is stated at initial cost and is adjusted for subsequent additional investments and the Company’s proportionate share of earnings or losses and distributions.

The Company records its proportionate share of the investee’s net income or loss, net of foreign taxes, one quarter in arrears as income (loss) from unconsolidated affiliates, net of foreign tax, in the Condensed Consolidated Statements of Income and its proportionate share of the investee’s other comprehensive income (loss), net of income taxes, in the Condensed Consolidated Statements of Comprehensive Income and the Condensed Consolidated Statements of Changes in Equity. The U.S. tax effect of the Company’s proportionate share of Tecumseh’s income or loss is recorded in income tax expense in the Condensed Consolidated Statements of Income. In general, the equity investment in unconsolidated affiliates is equal to the current equity investment plus the investee’s net accumulated losses.

The Company’s netincome from unconsolidated affiliates, net of foreign tax, for the quarter ended September 26, 2026 included losses of $3.1 million for Tecumseh. The Company’s net income from unconsolidated affiliates, net of foreign tax, for the quarter ended September 27, 2025 included income of$0.5 million for Tecumseh.

The Company’s netincome from unconsolidated affiliates, net of foreign tax, for thenine months ended September 26, 2026 included losses of$3.3 million for Tecumseh. The Company’s net income from unconsolidated affiliates, net of foreign tax, for thenine months ended September 27, 2025 included losses of$2.0 million for Tecumseh.

Retail Distribution

The Company owns a 28 percent noncontrolling equity interest in a limited liability company in the retail distribution business. This investment is recorded using the equity method of accounting. The Company records its proportionate share of the investee’s net income or loss one month in arrears as income (loss) from unconsolidated affiliates in the Condensed Consolidated Statements of Income. The Company’s proportionate share of the investee’s other comprehensive income (loss), net of income taxes, is recorded in the Condensed Consolidated Statements of Comprehensive Income and Condensed Consolidated Statement of Changes in Equity.

The Company’s netincome from unconsolidated affiliates, net of foreign tax, for the quarter ended September 26, 2026 included income of $4.8 million for the retail distribution business. The Company’s net income from unconsolidated affiliates, net of foreign tax, for the quarter ended September 27, 2025 included income of $3.2 million for the retail distribution business.

The Company’s netincome from unconsolidated affiliates, net of foreign tax, for thenine months ended September 26, 2026 included income of$12.0 million for the retail distribution business. The Company’s net income from unconsolidated affiliates, net of foreign tax, for thenine months ended September 27, 2025 included income of$8.1 millionfor the retail distribution business.

Note 9 –Debt

On March 27, 2026, the Company entered into a Credit Agreement to replace its prior credit agreement that matured on March 31, 2026. The Credit Agreement provides for an unsecured $100.0 million revolving credit facility, which matures March 27, 2031.

There wereno borrowings outstanding under the Credit Agreement as of September 26, 2026. Borrowings under the revolving credit facility bear interest, at the Company’s option, at the Benchmark Rate which is determined by the underlying currency of the Credit Extension, or the Base Rate as defined by the Credit Agreement, plus an applicable margin. Advances may be based upon the one, three, six, or twelve-month interest period. The applicable margin is based upon the Company’s debt to total capitalization ratio, and can range from 112.5 to 162.5 basis points for Benchmark Rate loans and 12.5 to 62.5 basis points for Base Rate loans. Additionally, a commitment fee is payable quarterly on the total commitment less any outstanding loans or issued letters of credit, and varies from 15.0 to 30.0 basis points based upon the Company’s debt to total capitalization ratio. Availability of funds under the revolving credit facility is reduced by the amount of certain outstanding letters of credit, which are used to secure the Company’s payment of insurance deductibles, certain retiree health benefits, and other corporate obligations.

Note 10 –Benefit Plans

Pension and Other Postretirement Plans

The Company sponsors several qualified and nonqualified pension plans and other postretirement benefit plans for certain of its employees. The components of net periodic benefit cost (income) are as follows:

The components of net periodic benefit cost (income) other than the service cost component are included in other (expense) income, net in the Condensed Consolidated Statements of Income.

Multiemployer Plan

On August 2, 2024, the Company entered into an equity purchase agreement to acquire all of the outstanding shares of Elkhart Products Corporation (Elkhart). Elkhart contributes to the IAM National Pension Fund (IAM Plan). The Employer Identification Number for this plan is 51-6031295.

The Company withdrew from the IAM Plan in 2025 and recognized $4.8 million in related expenses during the third quarter of 2025, which represents the Company’s best estimate of probable loss for the related withdrawal liability.

Note 11 –Commitments and Contingencies

The Company is involved in certain litigation as a result of claims that arose in the ordinary course of business, which management believes will not have a material adverse effect on the Company’s financial position, results of operations, or cash flows. The Company may also realize the benefit of certain legal claims and litigation in the future; these gain contingencies are not recognized in the Condensed Consolidated Financial Statements.

Environmental

Non-operating Properties

Southeast Kansas Sites

The Kansas Department of Health and Environment (KDHE) has contacted the Company regarding environmental contamination atthree former smelter sites in Kansas (Altoona, East La Harpe, and Lanyon). The Company is not a successor to the companies that operated these smelter sites, but has explored possible settlement with KDHE and other potentially responsible parties (PRP) in order to avoid litigation.

In February 2022, the Company reached a settlement with another PRP relating to these three sites. Under the terms of that agreement, the Company paid $5.6 million, which was previously reserved, in exchange for the other PRP’s agreement to conduct or fund any required remediation within the geographic boundaries of thethree sites (namely, the parcel(s) on which the former smelters were located), plus coverage of certain off-site areas (namely, contamination that migrated by surface water runoff or air emissions from the Altoona or East La Harpe site, and smelter materials located within 50 feet of the geographic boundary of each site). The settlement does not cover certain matters, including potential liability related to the remediation of the town of Iola which is not estimable at this time. The other PRP has also provided an indemnity that would cover third-party cleanup claims for those sites, subject to a time limit and a cap.

Altoona. Another PRP conducted a site investigation of the Altoona site under a consent decree with KDHE and submitted a removal site evaluation report recommending a remedy. The remedial design plan, which covers both on-site and certain off-site cleanup costs, was approved by the KDHE in 2016. Construction of the remedy was completed in 2018. Under the terms of the settlement with the other PRP, the Company expects the operations and maintenance costs for this remedy to be paid for entirely by the other PRP.

East La Harpe. At the East La Harpe site, the Company andtwo other PRPs conducted a site study evaluation under KDHE supervision and prepared a site cleanup plan approved by KDHE. In December 2018, KDHE provided a draft agreement which contemplates the use of funds KDHE obtained fromtwo other parties (Peabody Energy and Blue Tee) to fund part of the remediation and removes Blue Tee from the PRPs’ agreement with KDHE. Pursuant to the terms of the settlement with the other PRP noted above, the Company expects the remediation to be conducted and paid for entirely by the other PRP, and for that other PRP to negotiate and enter into an agreement with KDHE.

Lanyon. With respect to the Lanyon Site, in 2016, the Company received a general notice letter from the United States Environmental Protection Agency (EPA) asserting that the Company is a PRP, which the Company has denied. The EPA issued an interim record of decision in 2017 and has been remediating properties at the site. Approximately 1,371 properties were to be remediated. In August 2023, the EPA issued afive-year review indicating that the cleanup of approximately 300 remaining residential properties would be completed in 2026. A record of decision concerning the cleanup is scheduled for a future date.

Shasta Area Mine Sites

Mining Remedial Recovery Company (MRRC), a wholly owned subsidiary, owns certain inactive mines in Shasta County, California. MRRC has continued a program, begun in the late 1980s, of implementing various remedial measures, including sealing mine portals with concrete plugs in portals that were discharging water. The sealing program achieved significant reductions in the metal load in discharges from these adits; however, additional reductions are required pursuant to an order issued by the California Regional Water Quality Control Board (QCB). In response to a 1996 QCB Order, MRRC completed a feasibility study in 1997 describing measures designed to mitigate the effects of acid rock drainage. In December 1998, the QCB modified the 1996 order extending MRRC’s time to comply with water quality standards. In September 2002, the QCB adopted a new order requiring MRRC to adopt Best Management Practices (BMP) to control discharges of acid mine drainage, and again extended the time to comply with water quality standards until September 2007. During that time, implementation of BMP further reduced impacts of acid rock drainage; however, full compliance has not been achieved. The QCB is presently renewing

MRRC’s discharge permit and will concurrently issue a new order. It is expected that the new 10-year permit will include an order requiring continued implementation of BMP through 2036 to address residual discharges of acid rock drainage. The Company currently estimates that it will spend between approximately $13.7 million and $14.8 million for remediation at these sites over the next 30 years and has accrued a reserve at the low end of this range.

Lead Refinery Site

U.S.S. Lead Refinery, Inc. (Lead Refinery), a non-operating wholly owned subsidiary of MRRC, has conducted corrective action and interim remedial activities (collectively, Site Activities) at Lead Refinery’s East Chicago, Indiana site pursuant to the Resource Conservation and Recovery Act since December 1996. Although the Site Activities have been substantially concluded, Lead Refinery is required to perform monitoring and maintenance-related activities pursuant to a post-closure permit issued by the Indiana Department of Environmental Management effective as of March 2, 2013. Approximate costs to comply with the post-closure permit, including associated general and administrative costs, are estimated at between $1.9 million and $2.0 million over the next 11 years. The Company has recorded a reserve at the low end of this range.

On April 9, 2009, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the EPA added the Lead Refinery site and surrounding properties to the National Priorities List (NPL). On July 17, 2009, Lead Refinery received a written notice from the EPA indicating that it may be a PRP under CERCLA due to the release or threat of release of hazardous substances, including lead, into properties surrounding the Lead Refinery NPL site. The EPA identifiedtwo other PRPs in connection with that matter. In November 2012, the EPA adopted a remedy for the surrounding properties and in September 2014, the EPA announced that it had entered into a settlement with thetwo other PRPs whereby they will pay approximately $26.0 million to fund the cleanup of approximately 300 properties surrounding the Lead Refinery NPL site (zones 1 and 3 of operable unit 1) and perform certain remedial action tasks.

On November 8, 2016, the Company, its subsidiary Arava Natural Resources Company, Inc. (Arava), and Arava’s subsidiary MRRC each received general notice letters from the EPA asserting that they may be PRPs in connection with the Lead Refinery NPL site. The Company, Arava, and MRRC have denied liability for any remedial action and response costs associated with the Lead Refinery NPL site.

In June 2017, the EPA requested that Lead Refinery conduct, and the Company fund, a remedial investigation and feasibility study (RI/FS) of operable unit 2 of the Lead Refinery NPL site pursuant to a proposed administrative settlement agreement and order on consent. The Company and Lead Refinery entered into that agreement in September 2017. The Company has made a capital contribution to Lead Refinery to conduct the RI/FS with respect to operable unit 2 and has provided financial assurance in the amount of $1.0 million. The RI/FS remains ongoing, and the Company has reserved currently estimated costs associated with its completion. The EPA has also asserted its position that the Company is a responsible party for the Lead Refinery NPL site, and accordingly is responsible for a share of remedial action and response costs at both operable units 1 and 2 of the site.

In January 2018, the EPA issuedtwo unilateral administrative orders (UAOs) directing the Company, Lead Refinery, andfour other PRPs to conduct soil and interior remediation of certain residences at the Lead Refinery NPL site (zones 2 and 3 of operable unit 1). Subsequent thereto, the Company and Lead Refinery reached agreement with thefour other PRPs to implement thesetwo UAOs, with the Company agreeing to pay, on an interim basis, (i) an estimated $4.5 million (subject to potential change through a future reallocation process) of the approximately $25.0 million the PRPs then estimated it would cost to implement the UAOs, which estimate is subject to change, and (ii) $2.0 million relating to past costs incurred by other PRPs for work conducted at the site, as well as the possibility of up to $0.7 million in further payments for ongoing work by those PRPs. As of September 26, 2026, the Company has made payments of approximately $7.6 million related to the aforementioned agreement with the other PRPs. The Company disputes that it was properly named in the UAOs. In March 2022, Lead Refinery entered into an administrative settlement agreement and order on consent with the EPA, along with thefour other PRPs, which involves payment of certain past and future costs relating to operable unit 1, in exchange for certain releases and contribution protection for the Company, Lead Refinery, and their respective affiliates relating to that operable unit. The settlement became effective in September 2022. The Company reserved $3.3 million for this settlement at the end of 2021.

In March 2018, a group of private plaintiffs sued the Company, Arava, MRRC, and Lead Refinery, along with other defendants, in a civil tort action relating to the site. The Company, Arava, and MRRC have been voluntarily dismissed from that litigation without prejudice. In July 2024, Lead Refinery was granted partial judgment on the pleadings with respect to plaintiffs’ amended complaint and settled the litigation for a payment of approximately $0.1 million.

At this juncture, the Company is unable to determine the likelihood of a material adverse outcome or the amount or range of a potential loss in excess of the current reserve with respect to any remedial action or other litigation relating to the Lead Refinery

NPL site, either at Lead Refinery’s former operating site (operable unit 2) or the adjacent residential area (operable unit 1), including, but not limited to, EPA oversight costs for which the EPA may attempt to seek reimbursement from the Company, and past costs for which other PRPs may attempt to seek contribution from the Company.

Bonita Peak Mining District

Following an August 2015 spill from the Gold King Mine into the Animas River near Silverton, Colorado, the EPA listed the Bonita Peak Mining District on the NPL. Said listing was finalized in September 2016. The Bonita Peak Mining District encompasses 48 mining sites within the Animas River watershed, including the Sunnyside Mine, the American Tunnel, and the Sunbank Group. On or about July 25, 2017, Washington Mining Company (Washington Mining) (a wholly-owned subsidiary of the Company’s wholly-owned subsidiary, Arava), received a general notice letter from the EPA stating that Washington Mining may be a PRP under CERCLA in connection with the Bonita Peak Mining District site and therefore responsible for the remediation of certain portions of the site, along with related costs incurred by the EPA. Shortly thereafter, the Company received a substantively identical letter asserting that it may be a PRP at the site and similarly responsible for the cleanup of certain portions of the site. On or about January 7, 2025, a similar general notice letter from the EPA was received by MRRC (also a wholly-owned subsidiary of Arava), stating that MRRC may be a PRP at the site. Collectively, the general notice letters identify three other PRPs at the site. The U.S. government and State of Colorado have expressed their interest in discussing potential cost recovery claims against Washington Mining, MRRC and/or the Company, and ahead of anticipated discussions, tolling agreements have been entered into. At this juncture, however, no specific actions have yet been required and the Company is unable to determine the likelihood of a materially adverse outcome or the amount or range of a potential loss with respect to any litigation (including any enforcement action by the U.S. or any state) or remedial action related to the Bonita Peak Mining District NPL site, nor is the Company able to determine the outcome of potential litigation over indemnification rights that Washington Mining may assert against any third party in relation to the site.

Operating Properties

Mueller Copper Tube Products, Inc.

In 1999, Mueller Copper Tube Products, Inc. (MCTP), a wholly owned subsidiary, commenced a cleanup and remediation of soil and groundwater at its Wynne, Arkansas plant to remove trichloroethylene, a cleaning solvent formerly used by MCTP. On August 30, 2000, MCTP received approval of its Final Comprehensive Investigation Report and Storm Water Drainage Investigation Report addressing the treatment of soils and groundwater from the Arkansas Department of Environmental Quality (ADEQ). The Company established a reserve for this project in connection with the acquisition of MCTP in 1998. Effective November 17, 2008, MCTP entered into a Settlement Agreement and Administrative Order by Consent to submit a Supplemental Investigation Work Plan (SIWP) and subsequent Final Remediation Work Plan (RWP) for the site. By letter dated January 20, 2010, ADEQ approved the SIWP as submitted, with changes acceptable to the Company. On December 16, 2011, MCTP entered into an amended Administrative Order by Consent to prepare and implement a revised RWP regarding final remediation for the site. The remediation system was activated in February 2014. Costs to implement the work plans, including associated general and administrative costs, are estimated to approximate between $0.9 million and $1.1 million over the next five years.

United States Department of Commerce Antidumping Review

On December 24, 2008, the Department of Commerce (DOC) initiated an antidumping administrative review of the antidumping duty order covering circular welded non-alloy steel pipe and tube from Mexico for the November 1, 2007 through October 31, 2008 period of review. The DOC selected Mueller Comercial as a respondent in the review. On April 19, 2010, the DOC published the final results of the review and assigned Mueller Comercial an antidumping duty rate of 48.33 percent. On May 25, 2010, the Company appealed the final results to the U.S. Court of International Trade (CIT). On December 16, 2011, the CIT issued a decision remanding the DOC’s final results. While the matter was still pending, the Company and the United States reached an agreement to settle the appeal. Subject to the conditions of the agreement, the Company anticipated that certain of its subsidiaries would incur antidumping duties on subject imports made during the period of review and, as such, established a reserve for this matter. After the lapse of the statutory period of time during which U.S. Customs and Border Protection (CBP) was required, but failed, to liquidate the entries at the settled rate, the Company released the reserve. Between October 30, 2015 and November 27, 2015, CBP sent a series of invoices to Southland Pipe Nipples Co., Inc. (Southland), requesting payment of duties and interest in connection with 795 import entries made during the November 1, 2007 through October 31, 2008 period. On January 26, 2016 and January 27, 2016, Southland filed protests with CBP in connection with these invoices, noting that CBP’s asserted claims were not made in accordance with applicable law, including statutory provisions governing deemed liquidation. On April 8, 2026, CBP denied the protests and demanded payment by Southland of approximately $5.1 million in duties and accrued interest. The Company continues to believe in the merits of the legal objections raised in Southland’s protests, but in the interest of avoiding litigation, Southland has submitted an offer to compromise CBP’s claims for approximately $0.5 million. Southland is awaiting a response from CBP to its offer. Given the procedural posture and issues raised by this legal dispute, the Company cannot estimate the amount of potential duty liability, if any, that may result from CBP’s asserted claims.

Guarantees

Guarantees, in the form of letters of credit, are issued by the Company generally to assure the payment of insurance deductibles, certain retiree health benefits, and debt at certain unconsolidated affiliates. The terms of the guarantees are generallyone year but are renewable annually as required. These letters are primarily backed by the Company’s revolving credit facility. The maximum payments that the Company could be required to make under its guarantees at September 26, 2026 were $27.4 million.

Note 12 –Income Taxes

The Company’s effective tax rate for the third quarter of 2026 was 26 percent compared with 26 percent for the same period last year. The primary item impacting the effective tax rate for the third quarter of 2026 was an increase related to the provision for state income taxes, net of the federal benefit, of $12.0 million.

The primary items impacting the effective tax rate for the third quarter of 2025 were increases related to the provision for state income taxes, net of the federal benefit, of $11.0 million and other items of $4.0 million.

The Company’s effective tax rate for the first nine months of 2026 was 25 percent compared with 25 percent for the same period last year. The primary items impacting the effective tax rate for the first nine months of 2026 were increases related to the provision for state income taxes, net of the federal benefit, of $33.6 million and other items of $6.7 million.

The items impacting the effective tax ratefor the first nine months of 2025 were increases related to the provision for state income taxes, net of the federal benefit, of $27.9 million and other adjustments of $5.0 million.

The Company files a consolidated U.S. federal income tax return and numerous consolidated and separate-company income tax returns in many state, local, and foreign jurisdictions. The statute of limitations is open for the Company’s federal tax return for 2022 and all subsequent years. The statutes of limitations for most state returns are open for 2022 and all subsequent years, and some state and foreign returns are also open for some earlier tax years due to differing statute periods. While the Company believes that it is adequately reserved for possible audit adjustments, the final resolution of these examinations cannot be determined with certainty and could result in final settlements that differ from current estimates.

Note 13 –Accumulated Other Comprehensive Income (Loss)

AOCI includes certain foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency, net deferred gains and losses on certain derivative instruments accounted for as cash flow hedges, adjustments to pension and OPEB liabilities, and other comprehensive income attributable to unconsolidated affiliates.

The following tables provide changes in AOCI by component, net of taxes and noncontrolling interests (amounts in parentheses indicate debits to AOCI):

Reclassification adjustments out of AOCI were as follows:

Note 14 –Insurance Claims

Prior to its acquisition by the Company, Bison initiated litigation against several of its insurance carriers related to a claim that it made for weather-related roof damage in April 2023. In September 2026, the lawsuit was settled on mutually agreeable terms and, in connection therewith, the Company received a $4.4 million cash payment. The amount recorded in the Condensed Consolidated Statement of Income is net of legal costs.

In March 2023, a portion of the Company’s Covington, Tennessee manufacturing operation was damaged by a tornado. Certain inventories, production equipment, and building structures were extensively damaged. To date, $55.0 million of insurance proceeds have been received. During the second quarter of 2025, the Company recorded a pre-tax gain of $36.3 million, or $0.12 per diluted share after tax, for the excess of insurance proceeds received over the losses incurred for damaged inventories, equipment, and buildings, as there are no known contingencies and there is no expectation of repayment regarding the proceeds received to date and any additional costs associated with the event are expected to be minimal. During the third quarter of 2025, the Company recognized an additional pre-tax gain of $4.9 million, or $0.02 per diluted share after tax. The claim is not yet fully settled, and additional insurance recovery amounts are expected to be recorded in the future.