A Medicare overhaul is set to introduce a tiered system for people with chronic diseases that would see the most unwell patients receive $1795 in GP visits to manage their condition.

But doctors who have championed the revolutionary model say the government appeared to be cost-cutting, and it could fail from a lack of funding, leaving patients worse off.

"It turns out older GPs are not retiring after all'': Dr Bastian Seidel, president of the Royal Australian College of General Practitioners.

The first detailed blueprint of the government's cornerstone Health Care Homes trial shows a monthly bundled payment will replace the individual fee-for-service Medicare payments that GPs can claim for each visit to manage patients with chronic and complex health conditions.

The sicker the patient, the bigger the bundle, with those deemed to have a high risk chronic condition and complex needs – estimated to be 1 per cent of the population – attracting an average payment of $1795 a year.