Requiring New York health plans to cover in vitro fertilization would add up to 1.1 percent to premiums, according to a state study belatedly released today.

Based on the state’s average premiums for 2017, the additional cost would be as much as $234 a year for a family of four – far more than previous estimates from proponents of an IVF mandate.

For an average individual policy, 1.1 percent would be about $80 a year.

New York’s health insurance premiums are already the highest in the lower 48 states, in part because of dozens of coverage mandates previously imposed by the Legislature.

Governor Cuomo, who ordered the study last year, included an IVF mandate in his proposed budget last month. His version would apply only to large-group policies of 100 members or more, and it would limit coverage to a maximum of three IVF cycles.

The study from the state Department of Financial Services – a rare case of state officials analyzing the costs and benefits of an insurance mandate before enacting it – said coverage for three cycles would add between 0.7 percent and 0.9 percent to premiums.

An alternative proposal from Assemblywoman Aravella Simotas and Sen. Diane Savino would apply to insurance policies of all sizes and cover an unlimited number of cycles. DFS said this version would increase premiums from 0.9 percent to 1.1 percent.

A related requirement in both versions – covering the cryogenic preservation of eggs in women undergoing chemotherapy and other procedures likely to damage their fertility – would add an estimated 0.02 percent to premiums.

Supporters of the Simotas-Savino bill have said it would increase premiums by 55 cents per member per month, or $26 a year for a family of four. The premium impact estimated by DFS – based on findings from the actuarial firm Wakely Consulting – would be about nine times higher.

The DFS estimates are roughly consistent with a 2016 analysis from Massachusetts, where an existing IVF mandate has been found to add about 1 percent to premiums.

Cuomo said he limited his proposal to large groups because of a provision of the Affordable Care Act, which requires states that impose major new mandates after 2012 to reimburse the cost for individual policyholders and small groups.

If the Simotas-Savino bill were to become law, the state would potentially owe $98 million to $116 million per year to individual and small-group policyholders, the report said.

Under Cuomo’s proposal, the cost impact would be limited to the subset of large groups that are fully insured. The majority of larger companies are “self-insured” – meaning they bear the risk of their employees’ medical costs – and federal law exempts such plans from state regulation.

Although Cuomo took pains to avoid an additional cost to state government,  his mandate would increase premiums for affected large employers by an estimated $18 million to $22 million.

The DFS study found that expanding insurance coverage for IVF would encourage women to transfer fewer embryos per cycle, which reduces the risks of the procedure, and would respond to changes in society – such as the growing numbers of women who delay childbearing because of their careers, and of same-sex couples who want to have children.

The study also acknowledged that rising premiums make insurance less affordable and could cause some New Yorkers to lose coverage:

It is difficult to predict whether any increases from mandates in these areas would cause persons to drop coverage, and how many. However, given the potential premium increases referenced above, it is likely that some number of insureds who are barely able to afford their existing coverage will drop coverage as a result of a significant rate increase, all other things being equal.