The measure was introduced "to avoid financial considerations adding to public uncertainty and concern when COVID-19 was an emergent and unfamiliar disease," Singapore's Ministry of Health said in a statement on Monday.
“Currently, unvaccinated persons make up a sizable majority of those who require intensive inpatient care, and disproportionately contribute to the strain on our healthcare resources,” the Ministry of Health said.
“COVID-19 patients who are unvaccinated by choice may still tap on regular health care financing arrangements to pay for their bills where applicable,” it added.
Treatment costs will still be "highly supported and highly subsidised", Singapore's Health Minister and multi-ministry task force chair Ong Ye Kung said at a virtual media briefing.
Those who are partially vaccinated can access free COVID-19 treatment until 31 December, and the government will continue to foot the bill for those who are ineligible to get a jab, such as children under 12, and for people who have a medical exemption.
Singapore has one of the highest rates of vaccination against COVID-19 in the world, with 85 per cent of the eligible population fully vaccinated, with 18 per cent having received booster shots.
It's also not the first to crack down on those who refuse to get inoculated.
In September, Germany announced unvaccinated workers who are forced into quarantine by coronavirus measures would no longer receive compensation.
France announced in October that COVID-19 screening tests would no longer be free for unvaccinated people. The move meant that they would essentially have to pay to enter venues such as cafes and theatres after the introduction of a new law that means proof of vaccination, a recent negative test or of a recent COVID-19 recovery is required to enter many indoor venues.
And in Italy, private and public sector employees must show their Green Pass (a digital or paper vaccination certificate) when they show up to work, or they will be sent home without pay.
Those who try and flout the law face fines of up to €1,500 (AU$2,370).