The CMS Parts C & D Appeals Guidance: the operative rulebook for Part D too
Checked against the current rules on July 6, 2026.
42 CFR Part 423 sets the legal framework for a Part D appeal, but this one CMS guidance document — the same one Medicare Advantage's own appeals cite — is where the procedural detail a plan actually has to follow lives, in its own numbered Part D-specific sections.
Source: CMS Parts C & D Enrollee Grievances, Organization/Coverage Determinations, and Appeals Guidance (eff. July 6, 2026).
This guidance's own prior-authorization and utilization-management section spells out what a plan must do before denying a drug on PA grounds — including making its own clinical criteria available, which is the document an appeal usually has to compare a denial against.CMS Guidance § 40.4
Its own formulary-exceptions sections detail exactly what a plan's tiering and off-formulary exceptions procedures must include, filling in the operational detail behind the regulation's own broader exceptions-process rule.CMS Guidance § 40.5.2
This same document covers the standardized notices a plan must send at each stage — the denial notice's own required content, what a redetermination notice has to explain about further appeal rights, and the model language CMS expects a plan to use rather than its own paraphrase — which is why a notice missing information this guidance requires is itself worth flagging, not just accepting at face value.CMS Guidance § 60.3
How this differs from the regulation itself
42 CFR Part 423 sets the legal minimum; this guidance is CMS's own operational instruction to plans about how to actually comply with it day to day, so it's frequently more specific and more useful for checking a real denial against than the bare regulatory text alone — a plan that follows the regulation's letter but skips this guidance's own operational detail is still non-compliant.
CMS updates this guidance periodically; CaseWhy Appeals' corpus is refreshed monthly so a citation here reflects the current version, not a stale copy.
Where a rule explainer elsewhere in this pack cites a bare "42 CFR §" section, that's the underlying regulation itself; where it cites "CMS Guidance §" instead, that's this same operational document — the two are meant to be read together, not treated as competing sources, since the guidance exists specifically to implement the regulation rather than to restate or override it.
Sources — last checked July 6, 2026
- CMS Guidance § 40.4as of July 6, 2026
- CMS Guidance § 40.5.2as of July 6, 2026
- CMS Guidance § 60.3as of July 6, 2026
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By CaseWhy Appeals editorial. See how this content is produced. Not legal advice. Not affiliated with or endorsed by Medicare, CMS, or any health plan. A product of CaseWhy LLC.
