U.S. workers who contribute to health savings accounts (HSAs) may be better than comparable workers at saving for retirement.

Analysts at Fidelity Investments, Boston — a money manager with a large life insurance subsidiary — looked at 48,000 workers who ended 2010 with both Fidelity-managed HSAs and accounts in corporate 401(k) plans with records kept by Fidelity.

The average 401(k) balance was $71,500 for all 401(k) particiapnts and $170,500 for Fidelity 401(k) plan participants who were also Fidelity HSA holders.

The analysts tried to filter out the effects of income by performing a similar comparison of HSA-owning and non-HSA-owning workers in the same income category.

In the $20,000 to $40,000 annual earnings category, for example, the average 401(k) balance for a 401(k) plan-only participant was $19,000; the average 401(k) plan balance for a participant with an HSA was $30,000.

In the $100,000 to $150,000 earnings category, the average 401(k) balance was $159,000 for a worker without a Fidelity HSA and $260,000 for a worker with an HSA.

The difference may be partly due to differences in employers: Employers with generous 401(k) plan matching programs may also have generous HSA matching programs. But Fidelity HSA holders also have an above-average 401(k) plan deferral rate: The average deferral rate is 8.9% for the HSA holders and 8.2% for participants without HSAs.

“An HSA, like a 401(k), is a benefit that employers can offer workers to help create a culture of saving in the workplace,” William Applegate, a Fidelity vice president, says in a statement.

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