It’s based on employer mandates:

San Francisco, eager to put its own stamp on the health care debate, unveiled an ambitious plan Tuesday that would make it the first city in the nation to provide every uninsured resident with access to medical services.

When rolled out next year, the city’s 82,000 uninsured residents would become eligible for a wide array of benefits, regardless of employment or immigration status. The complex, $200-million-a-year plan requires funding from existing government sources, uninsured residents who will pay based on income and a mandated contribution from all San Francisco employers with more than 20 workers.