And while trying to stay healthy, McClanahan advises her clients to pay attention to their health care consumption habits. Figuring out what McClanahan calls your "health-care mindset" will help you budget for the medical care you need, which is critical for many of today's retirees on fixed incomes who don't have the luxury of a pension.

"People who go to the doctor for everything are going to have higher medical costs," said McClanahan. "So if you're seeing every doctor under the sun, you need to save more money."

Take especial care if you tend to rely on holistic medicine, McClanahan added, as that's not covered under most medical plans and can be quite expensive.

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But even if you're not going for homeopathic remedies, it's important to understand your health insurance. Just 7 percent of people between the ages of 55 and 64 felt knowledgeable about Medicare coverage options, according to the Merrill Lynch study.

Knowing what your plan does and does not cover can help you decide whether it's worth signing up for supplemental insurance or paying into a long-term care insurance plan.

While thinking about what you'll need in the event of long-term care, you should also go ahead and have frank discussions with your loved ones, McClanahan said. That means figuring out what you'll want medically when the situation takes a turn for the worst. For instance, will you seek aggressive treatment or would you prefer hospice?

"It's really important to have good directives in life," McClanahan advised. "Make clear with your family what type of lifestyle is desirable."

Doing so will not only save your loved ones much agony but will also help protect them from over-spending and having to dip into their own pockets for what might be unnecessary treatment.

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How to save on health care when planning retirement