ADHERENCE / PRACTICAL MATH
Learn proportion of days covered, explore a simplified PDC recovery calculation, and organize medication adherence improvement work for Medicare Part D.
A refill gap is a starting point for investigation. Learn what covered days mean, what a simplified recovery ceiling can tell you, and what it cannot.
Proportion of days covered compares covered days with days in the applicable treatment period. CMS Part D adherence measures include diabetes medications, renin angiotensin system antagonists for hypertension, and statins for cholesterol.
CMS · 2026 technical notes ↗The adherence measures use a member-level PDC threshold of at least 80%. A contract’s measure rate summarizes eligible members meeting that threshold; CMS then applies its measure-specific star methodology. These are different calculations.
CMS · 2026 technical notes ↗A refill record alone does not explain a person’s circumstances. For internal quality work, distinguish data lag, a changed prescription, difficulty obtaining medicine, and other unresolved questions. Route clinical questions to the treating team rather than treating a score as a medication instruction.
AdherenceStar · suggested operating practiceUse this educational workspace to turn the guide into a practical conversation with your team.
Open the companion field guide ↗Teaching model: fixed treatment period, one covered day per calendar day, no exclusions or adjustments. Maximum = (covered + period − elapsed) ÷ period. Required remaining days = max(0, ceil(0.8 × period) − covered).
A focused, four-step working guide for quality teams.
Read the field guide ↗SMS, voice, mail fallback, and a plan-controlled outreach agent remain upcoming delivery capabilities. Member-app push is deferred. Licensed PQA value sets and production reconciliation remain open prerequisites.
No. They are different approaches to measuring medication availability. This calculator illustrates covered days only; it is not a production implementation of either full specification.
No. Availability inferred from claims is not proof of ingestion. Use the information as a prompt for appropriate follow-up.
No. It excludes eligibility rules, exclusions, overlapping fills, inpatient adjustments, reversals and other specification details. It is a teaching model using your hypothetical inputs.
