NEW ORLEANS — Psychologists from Louisiana and Mississippi admitted participating in a $25 million Medicare scam by billing for unnecessary or nonexistent tests on nursing home patients across the Southeast, federal authorities said Wednesday.

As part of their guilty pleas, Beverly Stubblefield, 62, of Slidell, Louisiana, and John Teal, 46, of Jackson, Mississippi, admitted they’re responsible for more than $5.6 million in fraudulent claims submitted to Medicare, according to a Department of Justice news release.

Each pleaded guilty in New Orleans’ federal district court to one count of conspiracy to commit health care fraud.

In statements made as part of their pleas, the two say that they worked for two companies run by co-defendants scheduled for trial next month. They said those companies, Nursing Home Psychological Services Inc. and Psychological Care Services Inc., billed Medicare for tests that were not needed or not given at all to nursing home residents in Mississippi, Louisiana, Florida and Alabama.

Teal and Stubblefield admitted that they tested the same residents repeatedly, according to the agreements. Some of those patients were “non-responsive,” Stubblefield’s statement said.

Their co-defendants, Rodney Hesson, 46, and his mother, Gertrude Parker, 62, both of Slidell, are scheduled for trial Oct. 11.

The FBI and U.S. Department of Health and Human Services’ Office of Inspector General investigated the case for the Justice Department’s criminal division and the Medicare Fraud Strike Force for the Eastern District of Louisiana.