Children's Health Insurance Patterns: A Review of the Literature. B. WHAT IS THE MEDICAID PARTICIPATION RATE FOR CHILDREN?

12/19/1997

Estimates of the overall Medicaid participation rate for children have been undertaken by the following researchers and organizations: The Urban Institute, CBO, GAO, and CBPP. All used the March CPS for their estimates These estimates are presented below and summarized in Table IV.2. Estimates of the overall Medicaid participation rate varied depending on whether Medicaid underreporting adjustments were used, the complexity of the eligibility simulation, and the universe of children examined.

1. The Urban Institute

The Urban Institute used March 1996 CPS data with its TRIM2 microsimulation model to simulate the average yearly Medicaid participation rate for children age 0 to 17 in 1995. Urban Institute researchers found that an average of 26.4 million children were eligible for Medicaid and 22.1 million enrolled, for a participation rate of 83.6 percent.(4) This high participation rate incorporates the TRIM2 model's adjustment for Medicaid underreporting. As far as we can determine, none of the other estimates reported in Table IV.2 includes an adjustment for Medicaid underreporting. As a result, these other participation rates are likely to be depressed.

TABLE IV.2
ESTIMATES OF MEDICAID PARTICIPATION RATES FOR CHILDREN, BY SOURCE
Source Data Time Period Estimate Definitions and Eligibility Criteria Eligibles (millions) Enrollees (millions) Part. Rate
Urban Institute's

TRIM2 Model

(which adjust for Medicaid undercount)

CPS 3/96 1995 Estimate definition: Participation rate for all children age 17

Eligibility criteria:

State-specific poverty related

AFDC children

SSI children

Medically needy children

Assets

26.4 22.1 83.6%
Reschovsky et al. (1997) CTS late 1996 /early 1997 Estimate definition: Participation rate for all children age 17

Eligibility criteria: State-specific poverty-related criteria only

20.3 10.8 53.3%
CBO (Bilheimer 1997) CPS 3/96 1995 Estimate Definition: Participation rate for children who met expansion eligibility criteria.

Eligibility criteria:

Children receiving welfare cash assistance or covered by private insurance are excluded from all calculations. No other criteria specified.

- - 60%
GAO (1996) CPS 3/95 1994 Estimate definition:

Children age 11 eligible for Medicaid by federal mandate because of age and income eligibility.

Eligibility criteria:

Poverty-related only. Not state-specific. Only includes children age 5 with family incomes below 133% of poverty and children 6-11 with family incomes below 100% of poverty.

14.3 - -
Center for Budget and Policy Priorities (Summer et al. 1997) CPS 3/95 1994 Estimate definition:

Participation rate for children age 10.

Eligibility criteria:

Poverty related only. Not state-specific. Only the federal minimum poverty-related eligibility criteria for children age 10.

- - 66%
Estimate definition:

Participation rate for children age 10 who do not receive welfare cash assistance. This approximates the participation rate among children in poverty-related eligibility groups only.

- - 38

2. Congressional Budget Office

Using 1996 CPS data, CBO (Bilheimer 1997) estimated that in 1995 the Medicaid participation rate was 60 percent for children age 0 to 18 who did not receive welfare cash assistance and did not have private insurance. Their report did not provide details on their methodology for estimating Medicaid eligibility. It is our understanding that CBO does not routinely adjust its CPS estimates for Medicaid underreporting.

3. SIPP Estimates of Medicaid Eligibility

To date, there have not been any Medicaid eligibility estimates published using the SIPP. Blumberg et al. (1997) adapted The Urban Institute's TRIM2 microsimulation model to run on SIPP data for their study of crowd-out, but they have not yet reported any Medicaid eligibility or participation rate estimates.

4. Estimates for Poverty-Related Expansion Children Only

Both the GAO (1996) and the CBPP (Summer et al. 1997) used the March 1995 CPS to estimate Medicaid participation for the subset of younger children eligible for Medicaid by federal mandate. As stated in the previous section, this included all uninsured children age 0 to 5 in families with incomes below 133 percent of poverty and uninsured children born after September 30, 1983 with family income below 100 percent of poverty. GAO did not calculate a Medicaid participation rate per se. However, it estimated that 14.3 million children under age 11 in 1994 were eligible for Medicaid by federal mandate because of age and family income. Of those, 11.4 million had private or public insurance coverage and 2.9 million were uninsured. Thus, they estimated insurance coverage (public or private) of 79.7 percent for this Medicaid eligible subset of children.

CBPP found that approximately two-thirds of the children age 0 to 10 who were eligible for Medicaid were enrolled in the program in 1994. When they excluded all children receiving welfare cash assistance from their calculations in order to isolate the participation rate among those eligible for Medicaid under the expanded poverty-related groups, they found that the participation rate dropped to 38 percent.(5)