City leaders said the regulation risks undermining the Affordable Care Act exchanges and adding new costs for local governments. Now, they’re suing to overturn the rule.

City leaders said the regulation risks undermining the Affordable Care Act exchanges and adding new costs for local governments. Now, they’re suing to overturn the rule.

A group of cities is suing the feds to challenge recently finalized changes to the Affordable Care Act's marketplaces, which they say could lead 3 million people to lose coverage.…