This paper examines the distributions of four characteristics of people without any type of health insurance at five points in time covered by the 1984 Panel (or first sample) of the SIPP: September 1983, March 1984, September 1984, March 1985, and September 1985. The distributions of the age, region of residence, family income, and labor force status of the uninsured found in the SIPP are compared to the same distributions of the uninsured found in the March 1984 Current Population Survey (CPS).