The Fed opens its meeting in the wake of a 16-day partial government shutdown that made it all but certain the central bank will continue its bond buying program.
The Dow Jones industrial average rose 54 points, or 0.4 per cent, to 15,621 shortly before noon Tuesday.
The Standard & Poor's 500 index climbed four points, 0.3 per cent, to 1,766.
The Nasdaq composite slipped two points, 0.1 per cent, to 3,937.
Masco rose 78 cents, or 3.7 per cent, to $21.70 after the maker of cabinets, plumbing fixtures and other building products said late Monday that new home construction helped push its income higher.