GPs say they spend too much time working for free and the government needs to stump up more cash.
A new survey of 400 doctors shows they are paid for just 56 percent of the hours they work because the funding model is based only on the time spent in front of patients.
The rest of the time is spent doing administration, training and managing a practice, which is unpaid.
Royal New Zealand College of General Practitioners president Dr Samantha Murton says that needs to change.
"I think what we need to do is review the way that the funding's formulated and base it on all of the work, not just part of the work."
More work would go into building the case for an improved funding model, she said.
"From here, we look at what a patient load should be for a GP working a 40-hour week, what does that mean. We look at the way funding is calculated and how could we change the formulation for that. Then also look at how we support all the other activities that go on so that we can make sure doctors aren't working enormous numbers of hours just to make ends meet."
Dr Murton said it was not unreasonable for GPs to ask for dedicated and remunerated time to do patient follow-up and administration.
Another survey would take place that would be easier for members to take part in - this one was time-consuming and tricky to fit into a busy work schedule, she said.
It involved participants logging the time they spent on patient consultations, non-contact clinical time, training and education, clinical government, and managing a practice every day for 14 days.