Nearly 3.2 million people were covered by high-deductible health plans in January, according to America’s Health Insurance Plans, a national trade association of health benefits companies.

The total is more than triple the number of people covered by the new breed of benefit less than a year earlier, the association says. The association surveyed companies that offer the high-deductible health plans, known as health savings accounts, or HSAs.

An HSA is an account to which individuals and employers can contribute pretax funds in the amount of their high deductible – typically between $1,000 and $5,500 – for future medical expenses. The accounts are available only in conjunction with high-deductible health plans.