After three previous extensions, it looks like Obamacare’s temporary high-risk pools for the some of the country’s sickest patients are finally closing as planned.

The high-risk pools were set up in each state four years ago as a bridge to Obamacare’s coverage expansion this year, when insurers can no longer deny people coverage or charge them more because of a pre-existing condition.

The Obamacare program, known as the Pre-Existing Condition Insurance Plan, at its height covered 115,000 people whose medical conditions made it difficult for them to find affordable coverage. Many of the PCIP patients had been undergoing treatment for cancer, diabetes and heart disease, and advocates worried that vulnerable patients could experience a coverage gap if the program shut down too early.

The PCIP program was originally supposed to sunset at the end of December 2013, but it was extended until January as struggled. Then it was extended until March. Then it was extended until April 30.

That seems to be it for the extensions, though. Tanya Case, who heads a national association of high-risk pools predating the Affordable Care Act, said a Centers for Medicare and Medicaid Services official told her the program will end on April 30. Case said her organization doesn't plan to request another extension. A spokesman for CMS said he didn't have new information.

About 21,000 people were still enrolled in PCIP at the end of January, the most recent figures CMS has provided. That was down from about 77,600 at the end of December. Presumably, more people have found coverage since the end of January, and advocates feel comfortable seeing the program come to an end.