Lawmakers in 30 states are preparing to introduce legislation that would require large corporations to increase spending on employee health insurance – a measure the AFL-CIO endorsed late last week.

The so-called “Fair Share Health Care” bills are based on legislation passed in Maryland requiring companies with more than 10,000 workers to spend at least 8% of their payroll on health benefits or make payments to a state health insurance program. While the Maryland bill, which passed in April was later vetoed by the governor, an override could come next week when the Maryland legislature is back in session.

Currently Wal-Mart appears to be the only company in Maryland that would be affected by the legislation, but the push underscores state lawmakers’ growing frustration with the progress of federal healthcare reform.

Proposed legislation in Connecticut, Kansas, Florida, Colorado and Tennessee, among other states, vary but generally stipulate that a state’s largest private employers devote 8% to 11% of their payroll to health insurance or contribute a fee to a state fund. Some require nonprofit organizations to devote slightly less.