Idaho officials said they will begin allowing insurers to sell new plans that don’t meet requirements set by the Affordable Care Act, a move that will test the limits of states’ ability to carve out their own health-insurance rules under the Trump administration.

In a bulletin issued Wednesday, the Idaho Department of Insurance said that it would allow insurers in the state to begin offering “state-based plans” to consumers. These products could leave out some of the benefits mandated by the ACA for individual coverage. Insurers would be able to consider enrollees’ medical history in setting their premiums, a practice known as underwriting, which isn’t authorized under the ACA. The new state-based plans could also include dollar limits on total benefit payouts, which the ACA banned.

Health-policy experts said it isn't clear that the state has the authority to allow such products, or that it would be legal under federal law for insurers to sell them. “I don’t see how this is reconciled with the basic ACA requirements,” said Scott E. Harrington, a health-care-management professor at the University of Pennsylvania’s Wharton School.

Weston Trexler, a bureau chief in the Idaho Department of Insurance, said the state “believes we do have the authority to issue this bulletin and allow carriers to file…. we’ve looked at the issues there and we feel we can make these plans available.” The state will continue to enforce the ACA’s rules for ACA plans, he said, and the new products are “not conflicting with the ACA products.” He said they will provide a new option for consumers who can’t afford or don’t want the ACA-compliant plans, which have seen significant premium increases over the years.

The state’s move will put a spotlight on the federal Department of Health and Human Services and provide an early test of its newly confirmed, incoming leader, Alex Azar, who has criticized the ACA in the past but is now in charge of enforcing it. Mr. Azar has been expected to play a central role in Trump administration efforts to roll back the federal health law.