About 37% of large and midsize employers now offer health savings account plans or other health account plans, up from 28% in 2006.

Researchers at the consulting arm of Aon Corp., Chicago, and the International Society of Certified Employee Benefit Specialists, Brookfield, Wis., have presented those figures in a summary of results from an informal survey of 470 U.S. employers.

Only 17% of employers with HSA plans, health reimbursement arrangement plans or other health account plans offer a health account plan as the only plan option, but employers that do have health account plans say the health accounts are attracting more employees, the researchers report.

About 60% of participating employers with health account plans say the health account options have attracted more than 10% of the employees, up from 53% in 2006, the researchers write.

About 10% of health account programs offer both HRAs and HSAs.

Employers have built 48% of the health account programs around HSAs and 42% around HRAs.

About 11% of the participating employers that do not have health account plans today told the researchers they expect to offer health account plans either this year or in 2008.