The peak body for doctors is pushing for a radical overhaul of how Medicare funds GP visits, calling for a new model in which Australians enrol with one GP practice and get block funding for their ongoing care.

The Australian Medical Association wants the model, which the federal government is trialling for elderly, chronically ill patients from July this year, to be extended first to children aged five years and under, then expanded to "the entire population".

In a pre-budget submission to the Morrison government seen by the Sydney Morning Herald and The Age, the AMA also called for a boost to total GP funding - including for longer consultations to enable doctors to take the time needed to treat patients with complex needs.

"This transformation is necessary to ensure general practice can rise to the challenge of delivering quality care - which is patient-centred and cost effective, and which will reduce patients' needs for more complex, high-cost health care," the submission said.