The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA) added prescription drug coverage to Medicare (Medicare Part D), beginning on January 1, 2006. Medicare's elderly and disabled beneficiaries can enroll in private plans that contract with Medicare to provide the drug benefit. People on Medicare can obtain the Medicare drug benefit through two types of private plans. Beneficiaries can join a prescription drug plan (PDP) for drug coverage only and get their other Medicare benefits through the fee-for-service program, as the majority of people with Medicare currently do. Alternatively they can join a Medicare Advantage (MA) plan, such as an HMO or regional PPO, that covers drugs and all other Medicare benefits. Private plans can operate in one or more of 34 PDP regions and 26 MA regions nationwide.
For more information, visit Kaiser's Resources on the Medicare Drug Benefit, available at http://www.kff.org/medicare/rxdrugbenefit.cfm.
Figures for Puerto Rico and the territories (American Samoa, Guam and the Virgin Islands) are listed, however these figures are excluded from national totals. These figures are also excluded from PDP region totals because Puerto Rico and the territories are excluded from the 34 PDP regions that comprise only the 50 states and the District of Columbia.

Mathematica Policy Research analysis of the CMS Prescription Drug Plan Landscape file.
For more information including regional level data, visit Kaiser's Medicare Health and Prescription Drug Plan Tracker at http://healthplantracker.kff.org/topicresults.jsp?i=35&rt=2.

PDPs: Prescription Drug Plans.
Premiums are for any PDP offered by any sponsoring organization in the geographic area of interest. Please note that the premium shown for the U.S. is not necessarily available in every PDP region. Premiums are unweighted (i.e. they are not weighted by either enrollment or eligibles).