(BPT) - The most important shopping seniors may do this season is for a Medicare prescription drug plan. Therefore, it’s one holiday shopping item that shouldn’t wait until the last minute.

New research from Express Scripts shows 84 percent of seniors (based on an analysis of Express Scripts Medicare (TM) 2011 PDP enrollment data) wait until the last minute to select a Medicare Part D plan, and half of all seniors will attempt to enroll specifically on Medicare Monday - the Monday following Thanksgiving, the busiest enrollment day of the year. In addition, many seniors are not aware that the Centers for Medicare and Medicaid Services (CMS) changed the enrollment deadline in 2011 to Dec. 7, thus trimming the enrollment period by three weeks.

“As a result of down-to-the-wire decision making, seniors risk overpaying because they do not have the time to shop, compare and ensure the plan they choose covers all of their pharmacy needs,” says Paul Reyes, host of the Ask the Pharmacist radio series and pharmacist for Express Scripts. “Choosing the wrong plan could end up costing hundreds of dollars or more because you’re locked in until next year’s enrollment period.”