The number of people under 65 with individual coverage, either through a private health insurer or through Medicaid, increased to close to 89 million, from only 64 million in 2009, the year before the ACA showed up.

The number of uninsured people fell to 26, from 45 million.

At small employers, the total number of health plan participants has started to stabilize at around 16 million, but only because about 24% of the employers with 50 or fewer employees now sponsor self-insured health plans.

"Unlike the large group market, self-funded small group coverage provides a very clear value proposition to healthy groups, as they can gain the advantage of underwritten premiums, leaving less healthy groups to the guaranteed issue ACA single risk pool — creating the potential for the classic death spiral, where enrollment decreases until only the highest-cost groups are left in a high-morbidity, high-premium market," the authors of the new SOA institute report warn.

Related: The decline of the small-group health insurance market: Can policymakers save it?

The small employers in most states face no legal obligation to pay for health benefits of any kind. They are doing so only to compete with other employers for talent and because they think it's the right thing to do.

Some of the small employers with self-insured health plans have rocket scientists with master's degrees in public health for owners. But, in too many cases, business owners who may have only recently learned what a deductible is now have to shop for stop-loss insurance, choose pharmacy benefit managers, and bone up on health plan fiduciary risk, simply because they find the fully insured market, where the health insurer would make most of the complicated decisions, is too expensive.

The authors of the SOA institute report found nine states where fully insured small-group plans now cover fewer than 4% of residents under 65: Alaska, Georgia, Indiana, Kentucky, Missouri, Nebraska, Ohio, South Carolina and West Virginia.

Especially in states with a very small small-group health insurance market, small employers may give up on trying to offer group health coverage and instead use individual coverage health reimbursement arrangements or similar arrangements to send employees into the individual health coverage market, or they may simply give up on offering any health benefits, the actuaries warn.

"The small-group market is a significant example of an area where the ACA has fallen short of one of its original goals of access to affordable coverage," the actuaries conclude.

Today, members of Congress are trying to help small employers cope with the current problems in the fully insured market by let them use various strategies to escape from their states' small-group market regulations and conditions.

But Mark Meiselbach and Jean Abraham have published a Health Affairs paper hinting at another solution: Just say the whole U.S. small-group health plan market is in Iowa.

The authors found that the percentage of small firms offering fully insured group coverage increased in Iowa and just three other states between 2002 and 2023, while the percentage of small firms offering fully insured coverage fell in 46 states and the District of Columbia.

The Affordable Care Act now lets states impose many expensive benefits requirements on small employers.

State regulators say they know their markets best and should have the ability to develop rules that fit local needs. But, at least in the nine states where fully insured small-group health plan market might soon be smaller than the ICHRA market, maybe someone who wants the small-group market to survive would prefer to look into the idea of forming a voluntary small-group risk pool compact and doing what Iowa's doing, or find some other way to create a bigger small-group risk pool with lower costs for the small employers that are still struggling to offer health benefits.