In the CPS sample, qualified immigrants were significantly younger, poorer, more likely to have dependent children, to be married, and to be unemployed than the U.S.-born (). These characteristics are important determinants of Medicaid eligibility. Qualified immigrants were also much more likely to be Hispanic or Asian and much less likely to be black or white (). Before 1996, 19 percent of low-income qualified immigrants reported enrollment in Medicaid compared to 22 percent of the U.S.-born (). After 1996, the proportion of qualified immigrants enrolled in Medicaid fell by 25 percent to 13.8 percent, whereas for U.S.-born it fell by 9 percent to 20.4 percent ().
Characteristics of Qualified Immigrants and the U.S.-Born, before and after Welfare Reform
The results of the baseline regression model confirm these descriptive results after adjusting for demographic factors that might affect enrollment (). Prior to welfare reform, qualified immigrants were less likely to enroll in Medicaid than U.S.-born citizens (odds ratio [OR]=0.55; 95 percent confidence interval [CI], 0.51, 0.59) (). After welfare reform, there was a negative period effect on enrollment for both the U.S.-born and qualified immigrants (). Medicaid enrollment fell among the U.S.-born (OR=0.90; 95 percent CI, 0.87, 0.93) and qualified immigrants (OR=0.42; 95 percent CI, 0.38, 0.45) (). The test of whether the decline was greater for qualified immigrants is significant (p=0.008); after welfare reform, qualified immigrants had a significantly greater decline in Medicaid enrollment than U.S.-born citizens.
Logistic Regression of Medicaid Enrollment for U.S.-Born Citizens and Qualified Immigrants before Welfare Reform, 1994–1996
We also calculated the change in Medicaid enrollment by adjusting the U.S.-born population to the demographic characteristics of the qualified immigrants and generating absolute predicted probabilities of Medicaid enrollment and the associated confidence intervals for both groups by time period, from 1994–1996 and 1998–2001. The adjusted predicted probability of Medicaid eenrollment of low-income qualified immigrants dropped from 0.176 (95 percent CI, 0.169, 0.183) to 0.146 (95 percent CI, 0.139, 0.153). For the U.S.-born it dropped from 0.259 (95 percent CI, 0.252, 0.265) to 0.242 (95 percent CI, 0.236, 0.249). Thus, the enrollment dropped three percentage points (standard error [s.e.]=0.005, p<0.01) for the qualified immigrants and 1.6 percentage points (s.e.=0.003, p<0.01) for the U.S.-born; this 1.4 percentage point difference (s.e.=0.006) is statistically significant (p=0.012).
To answer the second study question about the effect of state policy on Medicaid enrollment after welfare reform, we examined enrollment for the U.S.-born and qualified immigrants in “not covered” and “covered” states using logistic regression (, Model 1). After welfare reform, Medicaid enrollment declined for both the U.S.-born (OR=0.87; 95 percent CI, 0.84, 0.91) and qualified immigrants (OR=0.73; 95 percent CI, 0.65, 0.83) in “not covered” states, with the decline being greater among qualified immigrants (, Model 1). In the “covered” states, enrollment also declined for qualified immigrants (OR=0.80; 95 percent CI, 0.70, 0.91), but did not change for U.S.-born citizens (, Model 1). To determine whether the decline in enrollment for qualified immigrants was less in “covered” states than in “not covered” states, we performed a significance test using an interaction term between immigrant status, time period, and state policy. The test was not significant (p=0.52), suggesting that Medicaid enrollment dropped similarly among qualified immigrants in “covered” and “not covered” states, and that state Medicaid policy did not buffer the negative effects of federal welfare reform.
Next, we constructed a regression model separating California from the other seven “covered” states (, Model 2), and determined whether the period effect of welfare reform on Medicaid enrollment was similar across states. A different picture emerges. Although the period effects on enrollment for the U.S.-born and qualified immigrants in “not covered” states shows a decline that is similar to the previous model (OR, U.S.-born=0.88; 95 percent CI, 0.85, 0.92; OR, qualified immigrants=0.73; 95 percent CI, 0.65, 0.83), the effect in the “covered” states is different when California is analyzed separately. When California is separated, Medicaid enrollment among qualified immigrants and the U.S.-born in the remaining 7 covered states does not decline significantly after welfare reform (OR, U.S.-born=1.00; 95 percent CI, 0.90, 1.10; OR, qualified immigrant=1.29; 95 percent CI, 0.86, 1.95) (, Model 2). In California, enrollment decreases significantly for qualified immigrants (OR=0.76; 95 percent CI, 0.66, 0.87), but does not change for the U.S.-born (, Model 2).