Republicans have failed to repeal and replace the Affordable Care Act. Now, can it be repaired?

The seven-year-old law has survived Supreme Court decisions and aggressive attempts to extinguish it by Republicans in Congress and the White House. But even people who rely on its coverage agree that it still has big problems. The question for the roughly 20 million Americans who buy their own health coverage — and for millions of others who remain uninsured — is what can realistically be done to address their main concerns: high prices and lack of choice in many parts of the country.

“Everyone feels really scrunched by the prices we’re paying, and we have no options in Iowa,” said Catalina Ressler, 39, a psychologist outside Des Moines who pays $1,567 in monthly premiums. “Next year is going to be even worse.”

Ms. Ressler’s plan, which covers her family of four, also comes with a $7,000 deductible. Their insurer, Wellmark Blue Cross and Blue Shield, is pulling out of the Affordable Care Act marketplace in Iowa next year, leaving just one company, Medica, to possibly remain.

Citing the protracted uncertainty over the law’s future, many insurers have proposed big rate increases again for next year even though many are no longer incurring big losses in its marketplaces. People covered by one insurer in Maryland could see premiums rise by more than 50 percent if proposed rate increases go into effect, and premiums for plans in Virginia and Connecticut could increase more than 30 percent. In North Carolina, where rates are already among the nation’s highest, Blue Cross and Blue Shield of North Carolina wants an increase of nearly 23 percent but said it would have sought less than half that amount under more predictable circumstances.