A San Francisco healthcare law is prompting some businesses to raise prices and curtail hiring, but it also is showing early signs of pushing employers to defray medical costs for more workers. The ordinance puts San Francisco among a growing number of regions experimenting with universal healthcare. Despite challenges, experts say San Francisco's ordinance is making headway. About 18,000 people have enrolled in the city's health-services program, and local businesses are seeking ways to cover healthcare costs for hard-to-insure workers.