It was a well-intentioned effort to provide men with some of the same financial protection from birth control costs that women get. But a new Maryland law may jeopardize the ability of thousands of consumers — both men and women — to use health savings accounts.

The law, which took effect Jan. 1, mandates that insurers cover vasectomies without requiring patients to pay anything out-of-pocket — just as they must do for more than a dozen birth control methods for women.

But the measure may run afoul of Internal Revenue Service rules that do not include vasectomies among approved preventive services for high-deductible health plans. People with health savings accounts — which are exempt from tax liabilities — tied to those plans could no longer contribute to the savings accounts in that case.