WASHINGTON — The Trump administration on Friday proposed new health insurance regulations that could affect basic benefits required by the Affordable Care Act, but not for a couple of years.

Loosening “Obamacare” benefit requirements was a major sticking point for congressional Republicans in thus-far fruitless efforts to repeal the law.

The complex new plan from the administration would give states a potential path to easing some requirements.

Starting in 2019, states could select from coverage levels in another state, which could be less generous. Ten broad categories of services required by the health law would still have to be covered, but the fine print could change.

Issued late in the day, the 365-page plan also proposes other changes to the inner workings of the health insurance markets created under the Obama-era law. The marketplaces offer subsidized private plans to people who don’t have access to job-based coverage. The changes proposed by the Trump administration cover areas from consumers’ eligibility for subsidies to how insurers are reimbursed.

It could take days for consumer groups, insurers, benefits experts and others to assess the potential impact of the proposal. Among the biggest uncertainties is whether the proposed changes would appeal to state officials, who generally try to protect standards established on their home turf.

The basic benefits that could be affected include:

— Outpatient, inpatient and emergency care

— Prescription drugs and labs

— Preventive care

— Pregnancy, maternity and newborn care

— Mental health and substance abuse

— Rehabilitation

— Children’s services, including vision and dental

While those categories are established by law and can’t be changed in a regulation, the fine print can make a big difference. For example, insurers can cover certain drugs, but not others, for a given medical condition. Expensive treatments for complicated chronic illnesses can be subject to limits on the number of visits the plan will cover.

The Trump administration’s proposal also called for changes to small business health insurance markets created by the ACA.