Amid all the news coverage of the GOP’s spending-bill extravaganza—the late-night deficit debates, the strategy sessions, the hallway blanket-wearing—one piece of the package has received comparatively little attention: a provision that would block abortion clinics from receiving Medicaid funds for any of the non-abortion services they provide.

During the past three years, abortion restrictions have mostly taken effect mostly in red and purple states—where legislatures have voted to enact them. But if this proposed provision passes, clinics all over the country will be affected. It would “have a pretty devastating impact on a lot of providers,” Mary Ziegler, a legal scholar and an Atlantic contributor, told me. Some would probably close, and others would have to limit the number of patients they serve. It’s “a really big deal,” she said, with perhaps the most significant consequences for abortion access since the passage of the 1976 Hyde Amendment, which bans federal funds for abortions in most cases.

All of this is complicated—which helps explain the dearth of attention to the matter. But funding for independent abortion providers works like this: Clinics receive money from a variety of sources, including local donations, insurance payments, and Medicaid reimbursements. (Yes, the Planned Parenthood Federation of America receives millions in contributions every year, but most of those funds are earmarked for advocacy, Ziegler told me.) A big percentage of Planned Parenthood’s patient pool relies on Medicaid. In keeping with the Hyde Amendment, providers are not reimbursed for abortions, but they do receive federal payments for other services, such as breast-cancer screenings, Pap smears, and STI testing. This new legislation would make Planned Parenthood and other clinics ineligible for any kind of Medicaid reimbursement, Ziegler said.

If clinics are not paid for these services, then, in many cases, they won’t be able to provide them. Maybe some clinics would be able to find funds from state legislatures or local donors to fill in the gaps, but many wouldn’t. An initial version of the bill passed by the House would have blocked Medicaid funding for 10 years, but the current version, which passed the Senate earlier today, would prohibit that funding for just one year after the law’s passage. (That’s right—we’ll all be back here again soon.)