Health savings accounts are an attractive and often underappreciated retirement tool for many Americans.

Every year, more people become eligible for an HSA when they enroll in a high-deductible health insurance plan. Employers promote this type of coverage as a way to shift the cost burden to employees. Lower premiums and HSA eligibility are key incentives.

HSAs are tax-advantaged much in the way that IRAs and 401(k)s are. Funds contributed to the account are tax deductible and grow untaxed. Withdrawals are not taxed if used to pay for qualified medical expenses.

To be eligible, the minimum annual insurance deductible for 2017 is $1,300 for individuals and $2,600 for families; the maximum deductible is $6,500 for individuals and $13,100 for families. (See IRS Publication 969.)