U.S. SECURITIES AND EXCHANGE COMMISSION

FORM 12b-25

CUSIP Number: 629377508
Commission File Number: 001-15891

NOTIFICATION OF LATE FILING

(Check One): [X] Form 10-K [ ] Form 20-F [ ] Form 11-K [ ] Form 10-Q [ ] Form N-SAR [ ] Form N-CSR

For Period Ended: December 31, 2004

[ ] Transition Report on Form 10-K
[ ] Transition Report on Form 20-F
[ ] Transition Report on Form 11-K
[ ] Transition Report on Form 10-Q
[ ] Transition Report on Form N-SAR
For the Transition Period Ended: ____________

Nothing in this form shall be construed to imply that the Commission has
verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I
REGISTRANT INFORMATION

NRG Energy, Inc.

N/A

211 Carnegie Center

Princeton, New Jersey 08540

PART II
RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and (c) The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

PART III
NARRATIVE

State below in reasonable detail the reasons why Forms 10-K, 11-K, 20-F, 10-Q, N-SAR, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

Management of NRG Energy, Inc. is in the process of completing its assessment of the effectiveness of its internal control over financial reporting as required by Section 404 of the Sarbanes-Oxley Act of 2002, and therefore, we will not be able to timely file our Form 10-K for the fiscal year ended December 31, 2004, as due on March 16, 2005, without incurring an unreasonable amount of effort and expense. We expect to be able to file the Form 10-K within fifteen calendar days, on or before March 31, 2005.

(Attach extra sheets if needed.)

PART IV
OTHER INFORMATION

(2) Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If the answer is no, identify report(s).

[x] Yes [ ] No

(3) Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?

[x] Yes [] No

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

NRG Energy’s 2004 results will not be comparable to the corresponding prior year period for a number of reasons related to significant corporate events that have taken place during 2003, including emergence from bankruptcy, significant financing transactions, asset dispositions and the impact of fresh start reporting on NRG Energy’s financial reporting.

NRG Energy, Inc.

INSTRUCTION: The form may be signed by an executive officer of the registrant or by any other duly authorized representative. The name and title of the person signing the form shall be typed or printed beneath the signature. If the statement is signed on behalf of the registrant by an authorized representative (other than an executive officer), evidence of the representative’s authority to sign on behalf of the registrant shall be filed with the form.

ATTENTION