Budget papers show general patients who do not have concession cards and pay for their doctor's visits in full will have their Medicare refund for standard GP visits shrink by $5.

Medicare refunds for a standard $70 GP consultation will decrease from about $37.70 to $32.70 from July 2015.

Bulk-billed patients are set to be slugged a $7 co-payment for GP visits, blood tests and X-rays from next year. For concession cardholders and children under 16, the co-contribution will be for the first 10 services per annum.

For each $7 patient contribution, $5 will be invested in a new Medical Research Future Fund and providers will be allowed to keep the remaining $2.

As part of other changes in the budget, patients will pay $5 more for PBS prescriptions, while concession cardholders will pay an extra 80¢.

The Medicare Levy Surcharge and Private Health Insurance Rebate thresholds will not be indexed between July next year and June 2018.

The impact of the budget on Australia's health system has been met with criticism from the medical community, with GPs and health professionals concerned about the impact the new co-payment will have on vulnerable patients.

Under changes to come into effect from 2015, doctors will no longer receive bulk-billing incentives but rather they will be paid a “low gap incentive” - which they will receive only if they collect the $7 patient contribution.

Dr Thinus van Rensburg, who owns Tillyard Drive Medical Practice in Charnwood, is concerned how the changes will affect his most vulnerable patients, saying it put doctors "between a rock and a hard place" because they would lose out on the incentive payment if they did not charge the $7 patient contribution.

"What do we do with not only the very unwell patient who comes to the room, but the nursing home patient, the house visit, the elderly and the frail?'' he said.

"If you go to the nursing home, I don't charge anybody because it's just not a practical thing to try and collect money, so you're either going to have to develop a system where you collect $7 from their relatives each time you see them, or you choose to drop your income by $14.

"This will certainly make things like nursing home visits very, very hard to justify.''

Dr van Rensburg said about 40-50 per cent of his patients were bulk-billed.

He was also concerned about the impact of the $7 payment on patients who required frequent blood tests.

He said there would also need to be a major upgrade of the software systems used by GPs so the annual cap on patient contributions by concession cardholders and children under 16 could be monitored.

Sharon Friel, Professor of Health Equity, an ANU Public Policy Fellow, raised concerns about the implications the budget would have on health equity in Australia.

"A $7 co-payment for a visit to the doctor and increased costs of medicines will undoubtedly affect lower-income groups more than others, thereby potentially resulting in higher mortality and morbidity for some and increasing costs and suffering," she said.

Dr Liz Hanna, from ANU, said the Abbott government's boost to medical research was a "con job thrown in as a sweetener, hoping Australia will swallow the nasty pill of the demise of Medicare". She said the $7 co-payment was an attack on the health system.

Dr van Rensburg said he had not increased his fees for the past two years and he would have to seriously consider whether his business could afford to continue to offer bulk-billing.

"My concern is two-fold - it's both as a business owner but also in terms of my patients - the way they've structured is that if we try and be the good guy in terms of not charging the patient the $7, the financial penalty for any doctor who writes off that $7 is really quite substantial so it will be really hard to do, so that's going to compromise patient care because patients are going to be out of pocket. The government is making it is as hard as possible for the patient not to be out of pocket."