SecProbe.io

June 1 4, 2013

Via E -mail
W. Greg Dunlevy
Chief Financial  Officer
Kosmos Energy Ltd.
Clarendon House
2 Church Street
Hamilton, Bermuda HM 11

Re: Kosmos Energy Ltd.
 Form 10-K for Fiscal Year Ended December 31, 2012
Filed February 25, 2013
Form 10 -Q for Fiscal Quarter Ended March 31, 2013
Filed May 9, 2013
File No. 001 -35167

Dear Mr. Dunlevy :

We have reviewed your filing an d have the following comments.  In some of our
comments, we may ask you to provide us with information so we may better understand your
disclosure.

Please respond to this letter within ten business days by amending your filing, by
providing the requested information, or by advising us when you will pr ovide the requested
response.   If you do not believe our comments apply to your facts and circumstances or do not
believe an amendment is appropriate, please tell us why in your response.

After reviewing any amendment to your filing and the information you provide in
response to these  comments, we may have  additional comments.

Form 10 -K for  Fiscal Year Ended December 31, 2012

Summary of Oil and Gas Reserves, page 20

1. Please provide additional disclosure describing investments and progress made during the
year to convert proved undeveloped reserves to proved developed reserves.  For example,
disclose the capital expenditures made to convert proved undeveloped reserves to proved
developed reserves.  Refer to Item 1203(c) of Regulation S -K.

2. We note your disclosure makes reference to “continued field developmental drilling in
the Jubilee Field .”  Please tell us whether this activity resulted in the conversion of

W. Greg Dunlevy
Kosmos Ener gy Ltd.
June 1 4, 2013
Page 2

 proved undeveloped reserves to proved status during the fiscal year ended December 31,
2012.

Notes to Consolidated Financial Statements

Note 2. Accounting Policies, page 98

Restricted Cash, page 99

3. We note you are required to maintain a restricted cash balance to “cash collateralize
performance guarantees.”  Please expand yo ur disclosure to describe the terms of the
restrict ions.  Refer to Rule 5 -02(1) of Regulation S -X.

Depletion, Depreciation and Amortization, page 100

4. We note your accounting policy statement that “ Capitalized exploratory drilling costs that
result in a discovery of proved  reserves and development costs are amortized using the
unit-of-production method based on estimated proved oil and natural  gas reserves for the
related field. ”  However, it appears that the types of costs you describe are required to be
amortized on the basis of the total estimated units of proved developed reserves.  Please
confirm, if true, that your policy complies with FASB ASC 932 -360-35-7 and modify
your disclosure accordingly, or otherwise advise.

Note 15. Income Taxes, page 122

5. We note you disclose the effective tax rate for the various jurisdictions in which you
operate in your Form 10 -Q for the fiscal quarter ended March 31, 2013.  Please tell us
how you considered providing this type of disclosure as part of your annual repor t.

6. We note you have provided disclosure regarding the expiration of foreign net operating
loss carryforwards.  Please  expand your disclosure to more clearly indicate the specific
periods in which these loss carryforwards expire.  Refer to FASB ASC 740-10-50-3a.

Note 17. Commitmen ts and Contingencies, page 128

7. We note from your disclosure, with regard to litigation, regulatory examinations and
administrative proceedings that “ Although the outcome of these matters cannot be
predicted  with certainty,  management believes none of these matters, either individually
or in the aggregate, would have a material effect  upon the Company's financial
statements .”  Please provide disclosure here that is similar to the disclosure on page 66 of
your Form 10 -K regar ding the possible effect on your results of operations should an
unfavorable outcome occur.  This comment  also applies to your filings on Form 10 -Q.

W. Greg Dunlevy
Kosmos Ener gy Ltd.
June 1 4, 2013
Page 3

 Form 10 -Q for Fiscal Quarter Ended March 31, 2013

Notes to Consolidated Financial Statements

Note 14. Subsequent Event, page 20

8. It does not appear that you have disclosed an estimate of the financial effect of each
subsequent event disclosed .  For example, we note that your statement that you will
reimburse Antrim Energy Inc. “a portion of previously incurred exploration costs, as well
as carry the partner on future 3D seismic costs;” does not include the related amounts.
Refer to FASB ASC 855 -10-50-2 and expand your disclosure as necessary or otherwise
advise.

We urge all persons who are responsible  for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules require.   Since the company and its management are
in possession  of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

 In responding to our comments, please provide  a written statement from the company
acknowledging that:

 the company is responsible for the adequacy and accuracy of the disclosure in the filing;

 staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and

 the company may not  assert staff comments as a defense in any proceeding initiated by
the Commission or any person under the federal securities laws of the United States.

You may contact Jennifer O’Brien  at (202) 551 -3721  or Ethan Horowitz, Branch Chief,
at (202) 551 -3311  if you have questions regarding comments on the financial statements and
related matters.  Please contact me at (202) 551 -3740 with any other questions.

        Sincerely,

        /s/ Ethan Horowitz  for

        H. Roger Schwall
        Assistant Director