Assessment is a core element of evidence‐based practice, but thorough formal assessment can place a significant burden on clients. We evaluated the clinical viability of using planned missing data designs to reduce client burden. Data come from an archival dataset with 1342 participants. Although significant differences were found in scores with planned missing data versus real scores, the effect sizes for the differences were generally small. Scores with missing data had sensitivity and specificity scores generally above .90 when predicting real scores over clinical cutoffs and improvement in real scores. These findings offer useful information to agencies and researchers looking for ways to collect more data without losing its immediate clinical utility.