The Obama administration-proposed change would lift a requirement that insurers cover "all or substantially all" drugs for immunosuppressant drugs used in transplant patients, antidepressants and anti-psychotic medicines, The New York Times reported Friday.
Insurers would still be required to cover drugs used to treat cancer, HIV and seizures.
Opponents of the change include insurers, drug benefit managers, drug companies, patient advocates, and both Democrat and Republican lawmakers, the Times said.
"We've been scratching our heads over this," said John J. Castellani, the chief executive of the Pharmaceutical Research and Manufacturers of America, the drug-industry trade group. "Why is the administration trying to make such extensive changes to a program that isn't broken?"
The Obama administration said it believes that by removing some currently covered drugs from the drugs insurers are required to cover would create savings for beneficiaries and the Medicare program.
"We believe the Part D program has been a phenomenal success," said Jonathan Blum, principal deputy administrator of the Center for Medicare and Medicaid Services. But, he added, "We also see vulnerabilities in the program, and we have proposed for public input into ways to improve it."
A House subcommittee plans to hold a hearing on the change next week. The public will be able to comment on the proposal until March 7.