Republicans also intend to go after specific provisions. Senator Orrin G. Hatch of Utah, a senior Republican on the Finance Committee, has introduced a bill that would eliminate a linchpin of the new law: a requirement for many employers to offer insurance to employees or pay a tax penalty. Many Republicans also want to repeal the law’s requirement for most Americans to obtain health insurance.

Alternatively, Republicans say, they will try to prevent aggressive enforcement of the requirements by limiting money available to the Internal Revenue Service, which would collect the tax penalties…

In addition, Republican lawmakers may try to undo some cuts in Medicare, the program for older Americans. Many want to restore money to Medicare’s managed-care program and clip the wings of a new agency empowered to recommend cuts in Medicare. Recommendations from the agency, the Independent Payment Advisory Board, could go into effect automatically unless blocked by subsequent legislative action.