Many young people facing a debt of up to £100,000 are declining to study medicine due to financial reasons, the British Medical Association (BMA) said.
A review commissioned by the Department of Health said Northern Ireland needed 100 extra medical students a year to meet demand.
That could cost £30 million a year and see other services reduced, the department said.
Dr Tom Black, chairman of the Northern Ireland BMA Council, said: “If we are to increase the numbers of young people going into medical school to the recommended 445, we will also have to look at how we widen participation, how do we make sure that any young person, no matter what their background, is encouraged and supported to become a doctor.
“With a debt level of up to £100,000 on finishing training, many young people will simply decide not to study medicine.”
A study published by the University of Dundee found that Northern Ireland had the lowest proportion (3.2%) of medical students from the least affluent backgrounds in the UK.
Students have to take five or six-year courses, incurring greater costs.
Following graduation they spend a further two years training.
This is relatively low paid, £26,000 for the first year.
Ulster University had previously announced plans for a new graduate medical school at its Magee campus in Londonderry.
Its opening has been delayed because there is no Stormont Executive.
The latest review of medical places was led by Professor Keith Gardiner, chief executive and dean of the Northern Ireland Medical and Dental Training Agency.
It was commissioned by the Department of Health to determine the optimum number of places required in Northern Ireland.
The department’s permanent secretary Richard Pengelly said: “It is vital to maximise the impact on healthcare in Northern Ireland of the very significant investment already being made in undergraduate medical education.”
He added: “This report raises long-term, strategic and cross-cutting questions with major financial implications which will require decisions by ministers.”
The report contains 10 recommendations and the department has indicated it plans to act on some of them immediately.