According to a recent survey on Health Savings Accounts (HSAs) and High Deductible Health Plans (HDHPs):

• The number of people with HSA/HDHP coverage rose to nearly 15.5 million in January 2013, up from 13.5 million in January 2012 and 11.4 million in January 2011
• This represents an annual growth rate of about 15% over the last several years
• The share of persons covered by HSA/HDHP who were enrolled in large group plans was 68% in January 2013, up from 59% in January 2012
• Preferred provider organizations (PPOs) represented over 90% of HSA/HDHP plans

Source: "January 2013 Census Shows 15.5 Million People Covered by Health Savings Account/High-Deductible Health Plans (HSA/HDHPs)," America's Health Insurance Plans (AHIP), June 2013, http://www.ahip.org/HSA2013/