Updated

Conditions are so bad at the notorious Upper East Side clinic where Joan Rivers suffered a fatal complication in August that the feds are threatening to yank their Medicare reimbursements, The Post has learned.

A Sept. 5 inspection, or “survey,” found violations in the areas of management, staffing, surgical services and patient rights, according to a letter sent to Yorkville Endoscopy by the Centers for Medicare & Medicaid Services (CMS), a division of the federal Department of Health and Human Services.

The CMS letter does not detail those violations or say if they are directly related to Rivers’ death. The comedian suffered a fatal lack of oxygen after a “therapeutic complication” at the clinic, the city Medical Examiner’s Office has determined.

However, CMS by law must make the full inspection report and Yorkville’s response addressing the violations public within 30 days of their being filed. That would make the inspection report public within days.

Previously revealed problems at the clinic include that celebrity Manhattan throat specialist Dr. Gwen Korovin was allowed to work on Rivers without being authorized to be in the operating room.

The Rivers family’s lawyers, at the firm Gair, Gair, Conason, Steigman, Mackauf, Bloom & Rabinowitz, did not immediately respond to a request for comment on the CMS findings.

Click here for more on this report from the New York Post.