Health Savings Accounts are an excellent way to build a second retirement account. These tax-favored accounts, which have only been available since January of 2004, can be opened by anyone with a qualifying high-deductible health insurance plan. Once you open an HSA account, you can place tax-deductible contributions into it, which grow tax-deferred like an IRA. You may withdraw money tax-free to pay for medical expenses at any time.

The biggest reason more people don't retire before age 65 is lack of health insurance, and many Americans reach age 65 woefully unprepared for the medical expenses they'll face once they do retire. One of the most important long-term reasons for establishing an HSA is to build up some money for medical expenses incurred during retirement.

Fidelity Investments reports that the average couple retiring in 2006 will need $190,000 to cover medical expenses during retirement. This assumes life expectancies of 15 years for the husband and 20 years for the wife.

HSAs are, without exception, the best way to build up money to pay for medical expenses during retirement. You should not contribute any money to your traditional IRA, 401 (k), or any other savings account until you have maximized your contribution to your HSA. This is because only health savings accounts allow you to make withdrawals tax-free to pay for medical expenses. You can take these distributions anytime before or after age 65.

Your HSA contributions won't affect your IRA limits -- $3,000 per year or $3,600 for those over 55. It's just another tax-deferred way to save for retirement, with the added advantage being that you can withdraw funds tax-free if they are used to pay for medical expenses.

For early retirees who are healthy, a health savings account can also be a smart option to help lower their health insurance costs while they wait for their Medicare coverage. The older someone is, the more they can save with an HSA plan. For many people in their 50's and 60's who are not yet eligible for Medicare, HSAs are by far the most affordable option.