PEEKSKILL, N.Y. — In this small city about an hour from Manhattan, pregnant teenagers, laid-off professionals and day laborers without insurance receive care at a community health center that has been part of the social fabric here for nearly four decades.

Because of the sweeping federal health care law passed two years ago, the center, part of the Hudson River HealthCare network, received a $4.5 million grant last month to expand. It plans to add six more medical and seven more dental exam rooms, allowing it to see as many as 5,000 additional patients, many of whom are without insurance, on Medicaid or have limited coverage. An additional 730 community centers or so like it are to be renovated or built across the country in the next two years for patients like that.

Unless the Supreme Court says otherwise.

By the end of June, the court is expected to decide whether some or all of the Obama administration’s health care law is constitutional. While speculation has focused on how the decision would affect the future of the nation’s health insurance market, little attention has been paid to the tens of billions of dollars in federal money appropriated for a host of other provisions in the law.