Thank you for your inquiry about CMS2v10: Preventive Care and Screening: Screening for Depression and Follow-Up Plan. The measure is not proscriptive as to what depression screening tool can be used. Per the measure specification, the measure requires use of a normalized and validated depression screening tool developed for the patient population in which it is being utilized. We are not able to provide guidance on which depression screening tool is best for use, however, we encourage providers to use their best clinical judgement. If a provider has determined that the PHQ-4 is an appropriate "standardized depression screening tool" for patients, and they are documenting the result and follow-up plan (if applicable) in the EHR or medical record, then that would meet the intent of the measure. However, please note that the measure does not include additional screening as an acceptable follow-up plan to an initial positive depression screen.