In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. The Medicare Prescription Drug, Improvement, and Modernization Act and Centers for Medicare and Medicaid Services affirmation enabled pharmacists to use Current Procedural Terminology (CPT) codes for documentation and billing of clinical services. Despite legislative support and potential availability of pharmacists' clinical services, a gap may exist between the reported availability and actual prevalence of these services in real-world settings. The objective was to assess the prevalence of selected CPT codes (99605-99607, 98966-989968, and 99211-99215) in documenting and billing potential pharmacists' clinical services using recent available data. This retrospective study utilized the Merative MarketScan Medicare database from the period January 1, 2016, to December 31, 2020. The dataset included deidentified patient information and CPT codes. Patients with CPT codes for face-to-face medication therapy management (MTM) services (99605-99607), codes for telephonic assessment and management (A/M) services (98966-98968), and/or codes for evaluation and management (E/M) services (99211-99215) were identified from outpatient claims. Descriptive statistics, including prevalence rates, were calculated. This study was approved by an institutional review board and followed STROBE guidelines. There were claims data for 2,784,629 enrollees from 2016 through 2020. Prevalence rates varied during this period, with lower rates for MTM face-to-face CPT codes (0.06%) and telephonic A/M codes (0.58%), while E/M CPT codes showed higher prevalence rates (87%). Study findings exhibited a limited adoption rate for MTM CPT codes for billing pharmacists' clinical services. Future research may focus on assessing pharmacists' perceptions and identifying facilitators and barriers to using CPT codes in billing clinical services.