This is a good overview of Health Savings Accounts by Jim Blankenship.
When you have a Health Savings Account, you’re allowed to make contributions to the account that are deductible from your income. There are limits to the amount that is deductible each year, and these limits are set by the IRS.
In order to have a HSA, you must also have a High-Deductible Health Plan (HDHP), which is a health insurance policy that, as the name implies, has a high deductible. Qualified plans have a minimum deductible of $2,600 for families (for 2015) or $1,300 for singles. In addition, HDHPs have a maximum annual limit on the sum of the deductible and out-of-pocket expenses that you must pay. Out-of-pocket expenses include co-payments and other amounts, but do not include premiums paid. The maximum sum of deductibles and out-of-pocket payments for a qualified HDHP in 2015 is $12,900 for family coverage, or $6,450 for single filers.
Read the complete article here: Health Savings Accounts for 2015 – Getting Your Financial Ducks In A Row.