The sounds of protests over abortion issues at state Capitols across the country are fading as legislatures conclude divisive debates over new restrictions. But advocates on both sides of the issue are quietly watching to see how another volatile fight will soon play — this one over how insurers will choose to cover abortion in new marketplaces under the health care law.

The marketplaces, which are also known as exchanges, will start enrolling people on Oct. 1 and begin providing health insurance coverage to consumers on Jan. 1. The federal health care law to some extent puts the choice about abortion coverage in the hands of insurers — most of whom have made their decisions but not announced them.

Already, critics of abortion have passed laws in 22 states that ban any abortion coverage in the exchanges.

North Carolina may be next. Both chambers passed different versions of a bill that restricts abortion, and one of the provisions under discussion would limit coverage in the marketplaces. The North Carolina bill was one of several that sparked controversy this year in state capitals from Madison, Wis., to Austin, Texas.

While the state battles have captured national interest, the decisions by insurers have not.