After 15 years of operation, Thirroul Medical Centre will be forced to charge all its patients for the first time with the introduction of a "GP tax".
It is just one bulk-billing clinic throughout the nation that will be affected by the Abbott government's proposed $7 Medicare co-payment.
Dr Madhusudana Nagaraj - one of five doctors at the busy Lawrence Hargrave Drive practice - said centres that predominantly bulk billed would be faced with higher administration costs in order to collect the fee.
"At present, we have a straightforward simple system," he said. "If additional fees need to be charged for each and every patient, that will mean more administration, more manpower and it's going to have a significant impact on small businesses like this."
Labor has vowed to block the "GP tax", announced in the federal budget to take effect from July 1, 2015. Under the changes, a safety net would be introduced after the first 10 visits for pensioners, concession card holders and children under 16.
However, Dr Nagaraj said if people accessed a number of practices for those 10 consults, then it would be hard for clinics to determine when to waive fees.
"This is one of the areas where we will need clarification - do we rely on information provided by the patient on how many consultations they've had in a year, do we have to check with Medicare?" he said. "Checking these sorts of things is going to tie staff up even longer, which will in turn impact on the people waiting in the waiting room."
Dr Nagaraj said he could foresee other issues arising, which would be hard for staff to police, including people waiting until they had a long list of complaints so they got their $7 worth out of a visit, or trying to get attention for two or more people at once.
"If people come in with a range of complaints that take longer than your standard consult, then do they get charged for a long consultation?" he said. "And what if a parent brings in one child, but asks the GP to quickly check another - do they have to pay the co-payment twice?
"It's going to be very hard for administrative and medical staff to work out - and these are the sorts of issues that need to be clarified."
Aside from administrative concerns, Dr Nagaraj was worried that people would put off potentially life-saving visits to their GP for medical checks such as pap smears and breast examinations, or even childhood vaccinations.
"I'm very worried about this because early recognition and intervention is vital," he said.