EXHIBIT 2. Enrollment in Medicare Advantage (MA), by quintile of neighborhood disadvantage, 2009–18.

source Authors’ analysis of data from the Medicare Beneficiary Summary File, 2009–18. notes For each data point, the denominator is the number of all beneficiaries of that type in Medicare each year. The numerator is the number of those beneficiaries enrolled in an MA plan. Each beneficiary was assigned a Social Deprivation Index on the basis of their residence’s nine-digit ZIP code. The index was then classified into quintiles. Each line represents a quintile of social deprivation (quintile 1: Social Deprivation Index, 1–20; quintile 2: 21–40; quintile 3: 41–60; quintile 4: 61–80; quintile 5: 81–100). The average annual growth rate was 0.9 percent for the first quintile (representing the lowest level of deprivation) and 1.6 percent for the fifth quintile (representing the highest level of deprivation).