The Trump administration is giving almost 4,000 health care clinics around the country until September to prove that they are not referring women for abortions, VICE News has learned.

On Saturday, the administration told health providers that participate in the $286-million federal family planning program known as “Title X” that they have weeks to show they are complying with a new rule, put into effect this week, that clinics receiving Title X funds may not refer patients for abortions.

Founded in 1970, Title X is the nation’s only federal program dedicated solely to funding family planning services. It provides about 4 million low-income people receive services like STI tests, cancer screenings, and birth control each year.

Many clinics that participate in the Title X program don’t offer abortions, and it is already illegal to use federal funding to pay for abortions, except in limited circumstances.

Under the Trump administration’s changed rules, clinics must also must now financially separate any services that may involve abortion from those that don’t — a move that, Trump officials say, ensures that no funds intermingle and preserves the “integrity” of Title X’s family planning mission.

“It will absolutely change the way in which services are delivered across communities in this country,” said one Title X grant recipient, who asked to remain anonymous.

According to the guidance sent out to grant recipients on Saturday, clinics taking Title X money must send the administration an “action plan” that outlines how they plan to comply with the changes to Title X, dubbed “the Final Rule,” by August 19.

They must also submit a signed statement testifying that their program doesn’t offer abortions, and that abortion is not offered as a method of family planning.

Then, by September 18, providers need to give the Trump administration a statement declaring that their programs are in compliance with the changes. A requirement that facilities also physically separate abortion-related services from other offerings won’t go into effect until March 2020.

The guidance makes it clear that the rule changes are in effect and compliance was required as of Monday. But Trump officials said they won’t bring enforcement actions against providers as long as they demonstrate that they’re making “good-faith efforts” to follow the new rules.

Several grantees have already announced that they can’t accept the changes. As of this week, Planned Parenthood are no longer using Title X funds and are instead relying on limited emergency funds. (Planned Parenthood cares for about 40% of all Title X patients nationally.) Illinois will also stop accepting the funds, Gov. J.B. Pritzker said this week. And Maine Family Planning has said it will withdraw from the program entirely.

Several reproductive health groups and states have sued over the rule changes, which they say amounts to a “gag rule” on providers’ ability to refer patients for a legal procedure. But a panel of judges from the U.S. Circuit Court of Appeals for the 9th Circuit ruled earlier this month to let the changes go into effect while that litigation plays out.

Still, the news on Monday that the Trump administration would start enforcing the changes came as a surprise to providers in the Title X program. Diane Foley, deputy assistant secretary for the Office of Population Affairs, made the announcement in an evening email to grantees on Monday just as many had arrived in Washington, D.C. for a multi-day meeting with administration staffers.

The reaction to that email, according to one meeting attendee, was, “Well, now what do we do?”