Health benefits at firms with five or fewer workers are different than benefits at bigger firms.

Many owners of U.S. microbusinesses already get their health coverage from a government health insurance program: Medicare.

Ben Ryan has provided a look at where firms with five or fewer employees get their health insurance — if the owner or any of the employees have health insurance — in an analysis of data from a Gallup microbusiness survey sponsored by Sam’s Club, a unit of Walmart. Gallup polled 1,005 business owners ages 18 and older who live in the United States and the District of Columbia.

To qualify as a microbusiness, a firm had to have fewer than five employees even when the owner was included in the employee count.

Only 21 percent of the microbusiness owners with at least one employee provides health benefits — in part because many of the owners get their own coverage from an entity unrelated to the microbusiness.

Many microbusiness owners work for other employers either full-time or part-time.

About 20 percent of microbusiness owners who work full-time for themselves get their health coverage from a former employer, or a current part-time employer — and 20 percent get their coverage from Medicare. Only 39 percent of those employers get their coverage from their own group health plans, and 16 percent are completely uninsured.

When microbusiness owners work part-time, 28 percent get their health coverage from a separate or former employer, 22 percent from their own business, and 30 percent from Medicare. About 8 percent of the microbusiness owners who work part-time are uninsured.

The boss is especially likely to have Medicare at well-established microbusinesses. Fewer than 15 percent of the owners of microbusinesses that have been around for 10 or fewer years have Medicare, but 31 percent of the owners of microbusinesses that have been around for more than 20 years have Medicare.