This analysis of the SCHIP and Medicaid eligibility redetermination processes in 8 states finds that redetermination processes have not been simplified to the same extent as initial enrollment processes. Less than 50 percent of children appeared to retain SCHIP eligibility at redetermination. Between 10 and 40 percent of children were "lost" at redetermination because their parents never responded to renewal notices or submitted renewal applications. Failure to pay premiums may reflect several possible outcomes besides affordability. State data systems are unable to report precisely on the outcomes of the eligibility redetermination process.