Three reliability estimates are derived for the Bayes modal estimate (BME) and the maximum likelihood estimate (MLE) of θin computerized adaptive tests (CAT). Each reliability estimate is a function of test information. Two of the estimates are shown to be upper bounds to true reliability. The three reliability estimates and the true reliabilities of both MLE and BME were computed for seven simulated CATs. Results showed that the true reliabilities for MLE and BME were nearly identical in all seven tests. The three reliability estimates never differed from the true reliabilities by more than .02 (.01 in most cases). A simple implementation of one reliability estimate was found to accurately estimate reliability in CATs.