All 9,000 public-sector doctors will move to a new insurer this year once their current cover expires, in a move arranged by the Ministry of Health Holdings (MOHH).
This will likely push up the cost of medical indemnity insurance for the doctors in private practice, since the public sector employs two-thirds of the doctors here. This in turn could push up private healthcare costs.
MOHH started the process in January, with the new plan kicking in over the year as the doctors' existing insurance expires.
This leaves the London-based Medical Protection Society (MPS), a not-for-profit doctors' cooperative that covers most doctors here, with only the 4,500 in the private sector. Last year, it insured more than 11,000 doctors here against medical incidents. It covers legal as well as compensation costs should doctors be sued by patients.
While MPS said premiums are not determined by the number of doctors insured, industry players say otherwise.
A spokesman for the Life Insurance Association, Singapore said: "In general, insurance premiums would be lower if the number of people insured is larger. This is because there are more people to share the company's fixed administration costs and the claims trend would be more predictable."
She added that premiums could also be influenced by other factors, including the significance of the size of the group insured.
Dr Chia Shi-Lu, head of the Government Parliamentary Committee for Health, said the impact of MOHH's move might not be significant as "MPS is a cooperative with many more members outside Singapore".
MPS says there is no cross insurance with other countries, but Dr Chia said: "Rising claims in other regions have affected policies here, and likewise withdrawing public- sector doctors may not have such a big impact on them."
Ms Alison Metcalfe, head of medical services at MPS, said it was "disappointed" by the move, but added: "Our membership subscriptions are based on the anticipated claims experience, not on the number of members who contribute to the mutual fund."
MOHH said the coverage and premiums for the scheme, which it is obtaining from insurance broker Aon, are comparable to those offered by MPS, and will be paid by the public institutions where the doctors work.
On why MOHH decided to offer different insurance coverage, Dr Chia said: "I think this was partly in response to concerns about tail cover for some specialities."
Tail cover, or coverage for future suits against incidents that occurred while the doctor was insured, even after he has retired or left for private practice, is offered by Aon's group medical malpractice insurance programme.
An MOHH spokesman said: "Public healthcare doctors do not need to purchase separate tail coverage insurance of their own."
Tail cover is an important part of insurance coverage for doctors as they can be sued up to three years from the time the patient or family becomes aware that there has been negligence on the part of the doctor.
It is even more critical for obstetricians, as they can be sued for up to 24 years after the birth of a child. This became an issue in 2015, when MPS reduced the annual premium for obstetricians from $36,000 a year to just over $22,000, and at the same time, stopped coverage once a doctor stops paying the annual premium. Premiums have risen significantly since, with those for obstetricians going back up to $35,427 this year - or a 30 per cent increase from the previous year.
Following the uproar, MPS let doctors buy an additional five years of post-retirement protection at a special rate. But it still means no coverage for the remaining years these doctors are open to civil action.