Appendix Table 1.

Characteristics (Percent) of HRS and NHIS Records That Match or Do Not Match to Medicare Records

	NHIS-Medicare			HRS-Medicare
	Match	No Match	P-value	Match	No Match	P-value
Attributes Before Age 65
Uninsured	9.1	11.5	<0.01	13.2	7.5	<0.01
Publicly Insured	20.3	11.9	<0.01	16.9	6.3	<0.01
Female	52.3	52.3	0.92	54.2	51.0	<0.01
Married	73.8	75.1	0.03	70.6	72.2	0.17
Non-Hispanic Black	8.6	9.9	<0.01	8.7	11.2	<0.01
Hispanic	7.3	6.3	<0.01	6.3	8.1	<0.01
Non-Hispanic and Not Black or White	4.0	2.8	<0.01	2.1	2.6	0.19
Less Than High School	20.1	25.0	<0.01	22.2	23.5	0.24
High School Degree	36.7	37.9	0.07	39.4	37.5	0.10
Some College	21.7	25.2	<0.01	19.5	19.9	0.66
Income < $20,000	20.3	26.4	<0.01	22.3	21.9	0.66
Income >= $20,000, <$45,000	35.9	38.9	<0.01	27.4	24.0	<0.01
Health - Very Good	25.4	29.6	<0.01	31.0	30.1	0.45
Health - Good	30.0	28.8	0.28	30.0	33.3	0.03
Health - Fair	11.2	15.2	<0.01	17.4	15.1	<0.01
Health - Poor	7.7	4.7	<0.01	7.6	6.1	0.03

For the NHIS, the sample consists of 9,588 individuals who are under the age of 65 at the time of the survey, turn 65 before January 1, 2000, have non-missing information on survey variables and are not on public insurance at the time of the survey.

For the HRS, the sample consists of 9,227 individuals who are under the age of 65 at the time of the survey, turn 65 before January 1, 2004, have non-missing information on survey variables and are not on public insurance at the time of the survey.

P-value refers to the value associated with the difference between those who match or do not match with Medicare based on a Wald F test.