Kosmos Energy Ltd.

Our stockholders are entitled to one vote for each common share that is owned on the record date on all matters considered at the annual stockholders meeting. Our stockholders do not have cumulative voting rights. You may vote your shares at the virtual meeting or by proxy. To vote by proxy, you may submit your proxy and direct how to vote your shares by telephone using the toll-free number listed on the Proxy Card, via the Internet at the website listed on the Proxy Card or by marking, dating, signing and mailing the enclosed Proxy Card in the prepaid envelope provided. When using Internet or telephone voting, the voting systems will verify that you are a stockholder through the use of a company number for Kosmos Energy Ltd. and a control number unique to you. If you submit your proxy and direct how to vote your shares via the Internet or by telephone, please do not also mail the enclosed Proxy Card. If you plan to vote at the virtual annual stockholders meeting, you will need the control number included on your notice of internet

availability, proxy card or voting instruction form to be admitted to the virtual meeting as a stockholder, vote your shares and ask questions. Even if you currently plan to attend the virtual annual stockholders meeting, we recommend that you also submit your proxy as described above so that your vote will be counted if you later decide not to attend the virtual annual stockholders meeting.

If you receive more than one Proxy Card or voting instruction form, it means that your shares are registered differently or are in more than one account. Please provide voting instructions for all proxy and voting instruction cards you receive. If you wish to consolidate accounts, please contact Computershare Trust Company, N.A. or your broker, bank or other nominee. We will announce preliminary voting results at the annual stockholders meeting and publish the final results in a Current Report on Form 8-K filed within four business days after the end of the annual stockholders meeting.