An equating procedure for a testing program with evolving distribution of examinee profiles is developed. No anchor is available because the original scoring scheme was based on expert judgment of the item difficulties. Pairs of examinees from two administrations are formed by matching on coarsened propensity scores derived from a set of background variables. These two subsets of scores are then equated, treating the associated sets of test performances as equivalent. The method is applied to the scores in 2 years of a testing program for admission to tertiary education.