Like many Americans, you may have put money into a 401(k), Roth IRA, or some other investment vehicle with the hope of one day enjoying your retirement. But just saving money for a later date isn't enough. Determining whether or not your plan will allow you a comfortable retirement requires a critical look at several important variables.

Know your ideal retirement
Whatever lifestyle you choose for retirement will determine how much money you'll need to save. Decide how and where you will spend your time. That will help you figure out how much you need to pay for it.

Consider your life expectancy
It is important to select a realistic life expectancy based upon gender, age, and family history. Consider making plans based on the optimistic end of the scale; it's better for your money to outlive you, than you to outlive your money.

Account for rising medical costs

• Health problems and health care premiums increase with age.
• Industry experts predict that medical costs will rise around 15 percent annually.
• A 2006 Fidelity Investments study indicated that a retired couple without employer-sponsored health insurance can anticipate spending $200,000 on medical expenses.
• Long-term care insurance (LTCI) can help you cover the costs of extended care at home or in an assisted living facility that Medicare and Medicaid don't. Without adequate resources for long-term care, you could deplete your assets at an accelerated rate. This is especially important for women, who tend to outlive their husbands.