The number of US households owning a health savings account (HSA) increased ten-fold from 2005 to 2012-reaching 6.52 million. HSAs allow individuals enrolled in a qualifying high-deductible health insurance plan to save and pay for medical care tax free. Lorens Helmchen of George Washington University and coauthors studied US tax records to estimate growth in HSAs and identify patterns in HSA ownership.

In 2005, 0.33 percent of employers recorded HSA use among their employees. By 2012 this share had grown to 3.77 percent among all employers and to nearly one-fourth among the country's largest employers. Take-up of HSAs among employees at the largest employers nearly tripled.

High-income and older households were at least four times more likely to establish HSAs and fully fund them than low-income and younger households. These take-up patterns suggest that HSAs may be attractive for individuals who may have access to traditional health plans already.

Study: Health Savings Accounts: Growth Concentrated Among High-Income Households And Large Employers, Lorens A. Helmchen, David W. Brown, Ithai Z. Lurie and Anthony T. Lo Sasso, Health Affairs, doi: 10.1377/hlthaff.2015.0480, published September 2015.