Many Medicare recipients are happy with the coverage the plan offers, according to survey data released by Extend Health.

The survey of over 500 retirees found that 85 percent are either "very" or "somewhat" satisfied with Medicare. One of the top reasons retirees said they are satisfied with the plan is that they experience fewer billing and payment issues than they did with other forms of health coverage.

"Retirees on Medicare have long been among the most satisfied of all Americans with their health insurance coverage, and after 45 years of Medicare, we now know that two-thirds of retirees like Medicare as much or more than the group plans provided by their former employers," said Extend Health CEO Bryce Williams. "This is important information as large employers consider how best to honor their commitments to retirees for health benefits."

As of 2007, the Centers for Disease Control and Prevention says that there were 37.9 million people in the United States over the age of 65, the age at which a large number of people aim to retire and receive Medicare coverage.