RNZCGP chief executive Helen Morgan-Banda said the shortage could create health problems for many.
"There is soon going to be a major shortage of GPs in New Zealand and people who need to see one may not be able to access one," she said.
"In addition, the way the government funds GP visits means some people can't afford to see their GP while others get cheaper visits regardless of their income.
"There are more than 400,000 low income New Zealanders who are missing out on the government subsidy they are entitled to receive. This means these people cannot afford to see their GP - and their health is suffering."
RNZCGP data from 2014 shows that during that year, around half a million people chose not to see a doctor because of the cost, and 21 per cent of Maori and Pasifika people could not afford to go to the doctor when they needed to.
While government funding for GPs has increased in recent years, holistic solutions are needed, Morgan-Banda said.
A "missing generation" of younger GPs has emerged, she said, due to low numbers among graduates of the 1990s and early 2000s, with the introduction of student loans one of the factors impacting that trend.
Only a quarter of GPs were in their 40s in 2014, and the high numbers who trained in the 1980s, and who have been the mainstay of the workforce, are now reaching retirement age.
Government incentives have attempted to make inroads into the problem, and have included a change made approximately five years ago which saw GP trainees' conditions aligned with those of medical professionals training in hospitals.
Other initiatives are also being introduced, such as Health Care Homes and Patient Portal.
Health Care Homes is a model of practice being rolled out across GP surgeries designed to improve patient access to doctors by reorganising time and allowing for phone appointments.
Morgan-Banda said this would help doctors and patients ascertain together on the phone whether a face-to-face appointment was needed, or if the concern was able to be managed through the phone conversation. It would also mean physical appointments could decrease in number and increase in quality or length if necessary.
She said individual practices would decide if the service would have a cost and what that might be.
Patient Portal is an online dashboard where patients of enrolled practices can access medical records and test results, communicate with their doctor or other healthcare professional, and order repeat prescriptions, among other services. It is accessed via an app, and must be registered for through the doctor first.
Morgan-Banda said what the government had done so far was working to some extent, but wasn't nearly enough, and 300 more GPs a year were needed.
Investment was also lagging "significantly" behind other comparable countries.
