Tax-exempt hospitals, it’s time for your check-up.

To qualify as tax-exempt – a benefit that is worth billions of dollars annually for the nonprofit hospital sector – nonprofit hospitals must meet a “community benefit” standard, which requires them to make contributions to their communities. However, the law does not require a minimum amount of charitable activities, and hospitals are largely free to define for themselves what their “community benefit” is.

Although “nonprofit” does not mean “no profit,” tax-exempt hospitals have come under scrutiny in recent years for the magnitude of their profits relative to the amount of charitable care they provide. Recent reports have shown that as their revenue has increased, the amount of charitable care has declined. With limited oversight from the IRS, critics say these hospitals are behaving more like big businesses than the charitable endeavors they are supposed to be. This trend has attracted the attention of Congress.

Senate Finance Committee Chairman Chuck Grassley (R-Iowa) has been particularly focused on ensuring that the law is enforced by the Internal Revenue Service. A year ago, Sen. Grassley asked the IRS for information about how it was monitoring tax-exempt hospitals’ compliance with the federal tax code, particularly the community benefit requirements. This month, he sent the IRS more questions, this time asking for the results of the IRS’s reviews of tax-exempt hospitals, including how many hospitals had been found to be non-compliant.

During the 2017 tax overhaul, tax-exempt hospitals dodged any significant changes to the way they are regulated, but that doesn’t mean they’re out of the crosshairs. Scrutiny of their charitable activities and finances, along with a public debate over whether they’ve earned their tax breaks, will continue.