The Treasury Department has not sufficiently enforced rules for newer components of the Home Affordable Modification Program, according to a review released last week by the Government Accountability Office. Treasury officials acknowledge that the agency has not met all of the GAOs recommendations but made no guarantees of tighter enforcement. Treasury has experienced challenges in implementing the newer Making Home Affordable programs, the GAO said, citing problems with the Principal Reduction Alternative, Second Lien Modification and Home Affordable Foreclosure Alternatives programs.