X0303 4 2010-01-03 0 0001013871 NRG ENERGY, INC. NRG 0001361282 Hoffmann M Stephen NRG ENERGY, INC. 211 CARNEGIE CENTER PRINCETON NJ 08540 0 1 0 0 Sr VP & Pres, Western Region Common Stock, par value .01 per share 2010-01-03 4 F 0 675 23.61 D 7846 D On January 3, 2007, Mr. Hoffmann was issued 1,600 Restricted Stock Units ("RSU's") by NRG Energy, Inc. under NRG Energy, Inc.'s Long Term Incentive Plan (the "LTIP"). Each RSU is equivalent in value to one share of NRG's Common Stock, par value $0.01. On January 3, 2010, the RSUs vested. Pursuant to the LTIP, Mr. Hoffmann elected to satisfy his tax withholding obligation upon the exchange of common stock for RSU's by surrendering a number of shares of common stock having a value on the date of the exchange equal to the tax withholding obligation. This form is being filed to reflect the surrender of 675 shares of common stock to satisfy the grantee's tax withholding obligation. Includes 336 shares acquired under NRG Energy, Inc.'s Employee Stock Purchase Plan on December 31, 2009. /s/ M. Stephen Hoffmann 2009-01-05