Ten former N.F.L. players, including the former Washington Redskins running back Clinton Portis, were accused of defrauding one of the league’s retiree health care benefit programs out of $3.4 million for phony purchases of medical equipment, federal prosecutors said on Thursday.

Brian A. Benczkowski, assistant attorney general for the criminal division of the United States Department of Justice, said at a news conference that claims totaling $3.9 million were filed and $3.4 million was reimbursed as part of a system that involved kickbacks and the recruiting of players to take part.

According to the indictment, the individual claims, filed from June 2017 to December 2018, averaged $40,000 to $50,000 each for medical equipment that was never prescribed by doctors and never ordered or delivered. Instead, the players are charged with filing fraudulent claims to the plan and, after being reimbursed, sending kickbacks to the ringleaders.

The retired players “treated the plan like it was their own personal A.T.M.,” Benczkowski said.

Benczkowski said that there was no evidence that current players or doctors took part in the scheme and that the yearlong investigation would continue and might expand to include others. Benczkowski said that had the fraud continued, the tax-exempt status of the program for retired players, which was established by the league and the players’ union in 2006, could have been jeopardized, potentially forcing players who received legitimate payments to pay back taxes.