"Every year our web traffic goes up and our customer care center gets flooded with phone calls in the last few days of December. Invariably those phone calls are from people trying to update their coverage at the last minute. This year, people who call to make a 'last minute' change after December 7, will be too late. We've got a lot of work to do to make sure people on Medicare don't wake up on January 1, 2012 with a prescription drug benefit that no longer covers all of their medications or that they can't afford."

In addtion to enrollment changes, the Department of Health and Human Services announced enrollees will see their Medicare Advantage premium shrink by 4 percent next year. The agency has also said prescription drug premiums won't increase.

eHealth's phone survey also found that:

• Aware of the Annual Enrollment Period: 91 percent of people with Medicare prescription drug coverage knew of AEP and the majority (70 percent) planned to review their plan during AEP.
• Awareness of new Annual Enrollment Period: Lower income Medicare beneficiaries were among those most likely to be aware of the new enrollment dates; one-third (37 percent) with an annual income under $35,000 per year said they were aware of the new dates. By comparison, one-in-five (21 percent) of those earning between $75,000 and $100,000 per year were aware of the new dates.
• Expectations that their drug plans will change: When asked if they expected their current Medicare prescription drug coverage to change in 2012, nearly two-thirds (63 percent) of all respondents said they either did not expect their prescription drug coverage to change (44 percent), or didn't know if it would change (19 percent) in 2012.

These expectations are notable because Medicare prescription drug plans do often change from year to year, which can affect what a consumer pays out of their own pocket for prescription drugs.