Doctors are set to discuss how to get the Medicare system out of its mid-life crisis at the AMA's national conference in Brisbane.

Doctors are set to discuss ways to make the Medicare system more efficient after the federal government's failed plan for a GP co-payment.

The system needs to evolve, but the government is going about it the wrong way, Australian Medical Association president Brian Owler says.

The AMA insists the government's four-year indexation freeze on Medicare rebates amounts to a "co-payment by stealth" because it will force GPs to pass costs on to patients.

"This government seems to have a new agenda of shifting more costs back on to patients," Prof Owler said.

"There are ways of actually evolving the system where you actually protect the vulnerable."

The AMA's annual three-day conference starts in Brisbane on Friday.