For seniors, estimating their medical costs in advance is usually a shot in the dark.

Of more than 350 seniors age 65 and older, only 41 percent even try to predict out-of-pocket costs for medical appointments, services and treatments and of those who try, 78 percent get it right at least “sometimes” with more than one third getting it right “most of the time.”

The survey was fielded from April 12-19, 2011 by Extend Health, Inc., which operates the nation’s largest private Medicare exchange.

“From a consumer perspective, health care is different from almost any other market in that providers of medical services do not typically provide prices prior to delivering their services,” says Bryce Williams, CEO of Extend Health. “In addition, insurance companies – not consumers – usually negotiate prices and pay directly for medical services. This lack of transparency makes it difficult for consumers who want or need to know what things will cost in advance so they can prepare themselves financially.”

The questions and detailed results from the survey are as follows:

Do you ever try to estimate your out-of-pocket medical expenses (anything not covered by your health insurance) in advance of a medical appointment, service, treatment or hospital stay?

If you answered, "yes" to the previous question, how frequently are you able to accurately estimate in advance your out-of-pocket medical expenses for a given medical appointment, service, treatment or hospital stay?