Professor Ian Gilmore reviewed prescription charges for people with long-term conditions in England in a report published last week.
Health minister Lord Howe has said that changes to the prescription charge system would be considered in the context of the next spending review, due in the autumn.
Although the report's remit did not extend beyond long-term conditions, Professor Gilmore said that improvements in patients' concordance with medicines might well outweigh income received through prescription charges.
'I can see much merit in having free prescriptions,' he said.
Professor Gilmore's review has recommended that GPs assess patients' eligibility for exemption from prescription charges.
The BMA has also re-stated its call for prescription charges to be abolished for all patients in England.
Professor Gilmore said exemptions should last for three years and be based on a broad definition of long-term conditions, centred around the need for ongoing management and treatment.
He argued that the new system should be phased in through a gradual reduction in the cost of pre-payment prescription certificates.
GPC prescribing lead Dr Bill Beeby said the report was a fair review of a system that is in a mess. But he added that requiring GPs to make exemption judgments could undermine GP/patient relationships.
'In practice, people will decide not to have those discussions,' he said. 'It will lead to a fairly liberal interpretation.'
Dr Beeby said the GPC now expected the DoH to begin discussions on how exemptions might change.
'The ball is in (the DoH's) court,' he said. 'I hope it will talk to us about what it is going to do and I hope it is not going to take too long.'