Medicare, Medicare Supplemental & Medicare Advantage: Part III - Who enrolls in what plan?

A 2005 report by Emory University researchers and commissioned by the Blue Cross Blue Shield Association of America found the following:

Of eligible retirees, 18% percent only have Medicare coverage. It is important to note that 49% of African-Americans and 31% of Hispanics and 33% of Whites fall into this category. Over 30% of retirees have primary or supplemental coverage through employer or union retirement plans. Another 25% of those who are Medicare eligible purchase MedSup (Medigap) policies on their own. Another 13% are Medicare beneficiaries who are also on Medicaid or other public assistance plans. Medicare Advantage covers 13% of retirees (Today, this represents 10 million people.)
Of retirees without employer/union plans or Medicaid, 53% of Hispanics, 40% of African- Americans and 33% of whites are enrolled in Medicare Advantage plans.

Medicare Advantage plans are required to offer at minimum the same benefits as traditional Medicare. Many offer more coverage, including vision, dental and drug benefits. As a result, those with lower incomes (<$20,000) are quick to see the value in joining such programs. In fact, 18% of Medicaid eligible retirees join a Medicare Advantage program instead of Medicaid. [One wonders if this is because of the challenges in signing up for public assistance or because Medicare Advantage is preferred.] It was determined that Medicare Advantage plans provided a $1,128 per person savings to the state and federal government over Medicaid. According to the study, if Medicare Advantage was ended, 39% would join a MedSup plan. Another 39% would be left with only basic Medicare and 22% would join Medicaid. As discussed in the October 29th post, Congress is subsidizing benefits for Medicare Advantage enrollees. Poor and minority groups are disproportionately affected if these are eliminated. Since Medicare Advantage is more cost-efficient than Medicaid and has a 90+% satisfaction rate, perhaps there ought to be some means testing to qualify for these private sector programs. From a cost standpoint, perhaps would it be reasonable for government to encourage elderly Medicaid enrollees, in geographic areas where plans exist, to enroll in Medicaid Advantage programs.