Redetermination, then the Independent Review Entity — and why Part D's own IRE step isn't automatic
Checked against the current rules on September 23, 2026.
Once a coverage determination is denied, the enrollee has 65 days to ask the plan itself to redetermine it. What happens after that redetermination is where Part D's own rules genuinely diverge from Medicare Advantage's.
Source: 42 CFR Part 423, Subparts M & U — Part D Grievances, Coverage Determinations, Redeterminations, Reconsiderations, ALJ Hearings, Council Review, and Judicial Review.
A request for redetermination must be filed within 60 days of the date on the denial notice (with a 5-day mailing presumption added in practice), and the plan must decide within 7 calendar days for a drug not yet received, 14 calendar days for a payment request, or 72 hours if expedited.42 CFR 423.58242 CFR 423.590
If the plan misses its own deadline, that failure itself counts as an adverse redetermination, and the plan must forward the case to the Independent Review Entity within 24 hours — the enrollee doesn't have to do anything to trigger this.42 CFR 423.590
But a real, favorable, on-time redetermination decision that still upholds the original denial does NOT auto-forward. The enrollee has to actively request IRE reconsideration, in writing, within 65 days of the redetermination notice.42 CFR 423.600
What this means for your appeal
Don't assume a case is automatically moving forward just because the plan upheld its own denial on time — check the redetermination notice's own stated deadline for asking the IRE (C2C Innovative Solutions) for reconsideration, and calendar it the same way the original 65-day deadline was calendared.
This is the single most consequential difference between a Part D appeal and a Medicare Advantage one: a family used to Medicare Advantage's own auto-forward-on-upheld-denial behavior can reasonably assume the same thing happens here, and let the 65-day IRE window pass while waiting for a letter that isn't coming. The redetermination notice itself is the only reliable source for whether a next step is required — read it fully rather than treating an upheld redetermination as the end of the road or as something the plan will escalate on its own.
If the redetermination notice is silent, unclear, or doesn't explain how to request IRE reconsideration, that's itself a defect worth raising directly with the plan or with the SHIP counseling program in your state — the notice is required to explain the next step, not leave the family to guess at it.
Sources — last checked September 23, 2026
- 42 CFR 423.582as of September 23, 2026
- 42 CFR 423.590as of September 23, 2026
- 42 CFR 423.600as of September 23, 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.
