Medicare gives you 120 days to appeal a denial, an ERISA plan 180, and a claim returned as unprocessable gives you none

Medicare fee-for-service gives you 120 days to file the first appeal. A commercial ERISA plan gives at least 180. Medicare Advantage gives 60. Same denial, three clocks — and one class of rejection has none.

Start there, because it is where the most work gets wasted. A claim Medicare returns as unprocessable “does not meet the criteria to be considered as a claim, is not denied, and, as such, is not afforded appeal rights.”1 cms.gov That is CARC 16 with MA130, and it needs a corrected claim, not a letter. The denial code reference walks the combinations. Clerical errors are the same story from a different direction: a contractor “must process clerical errors (which includes minor errors and omissions) as reopenings, instead of as redeterminations,” and the list includes inaccurate data entry and duplicate denials.2 ecfr.gov

Read the remittance and sort into three piles before anyone writes a paragraph. Resubmit. Reopen. Appeal.

The clock that runs shortest is the one you probably work last

Medicare has five levels and each one narrows what you can still say

Filing and decision timeframes from 42 CFR 405.942, 405.950, 405.962, 405.970, 405.1002, 405.1016, 405.1100, 405.1102 and 405.1130.2 ecfr.gov Summary table cross-checked against CMS MLN006562.3 cms.gov CY 2026 thresholds from the CMS annual adjustment notice.4 federalregister.gov

One rule governs the whole ladder, and most teams find out about it at level three. Absent good cause, “failure to submit all evidence, including documentation requested in the notice of redetermination prior to the issuance of the notice of reconsideration precludes subsequent consideration of that evidence.”2 ecfr.gov Anything you hold back for the ALJ is gone. Send the complete record at level one and level two — CMS says the same thing in plainer words: include all relevant supporting documents with your first appeal request.3 cms.gov

Two mechanical notes. Each additional evidence submission after a reconsideration request is filed extends the QIC’s 60-day clock by up to 14 days, so one clean package beats four supplements.2 ecfr.gov And a non-participating provider is not a party. The patient has to sign a Transfer of Appeal Rights (CMS-20031) before you can appeal on your own behalf.3 cms.gov For out-of-network BH practices, that form belongs in the intake packet, not in the appeals queue.

The ERISA track is one or two levels, and the clock depends on when you billed

For a group health plan, the claimant gets at least 180 days from receipt of the adverse determination to appeal.5 ecfr.gov How fast the plan must answer depends on whether the service has happened yet.

29 CFR 2560.503-1(f)(2) and (i)(2). Retrieved 24 August 2026.5 ecfr.gov

Four provisions in that regulation are worth quoting back at a plan, and most appeal letters cite none of them. The review may not defer to the original decision and cannot be run by the person who made it or their subordinate.5 ecfr.gov Where the denial rests on a medical judgment, the plan must consult a health care professional “who has appropriate training and experience in the field of medicine involved.”5 ecfr.gov The plan must identify the experts whose advice it obtained, whether or not it relied on them.5 ecfr.gov And that consultant cannot be the one who denied it the first time, or that person’s subordinate.5 ecfr.gov

Exhaustion has teeth in both directions. If the plan fails to follow these procedures, the claimant is deemed to have exhausted internal appeals and may go straight to external review or to court.5 ecfr.gov6 ecfr.gov

After the final internal denial, a non-grandfathered plan owes an external review by an independent review organization. The claimant has four months from receipt of the notice to request it, the IRO has 45 days to decide, and an expedited external review must be decided within 72 hours.6 ecfr.gov The IRO must “review the claim de novo and not be bound by any decisions or conclusions reached during the plan’s or issuer’s internal claims and appeals process,” it may not be paid on the likelihood it supports a denial, and the process may impose no cost on the claimant.6 ecfr.gov

Expedited is a clinical status, not a tone of voice

Expedited review exists for claims involving urgent care — where the standard timeframe could seriously jeopardize life, health, or the ability to regain maximum function. A post-service claim for a residential stay that ended in March is not urgent, and asking for expedited handling on it burns credibility.

A concurrent denial mid-episode is a different matter, and there is a lever here worth knowing. Any claim a physician with knowledge of the patient’s condition determines is urgent “shall be treated as” urgent under the ERISA rule.5 ecfr.gov Under the ACA rules the plan “shall defer to such determination of the attending provider.”6 ecfr.gov Get that determination from the attending psychiatrist in writing, in the record, before the utilization reviewer sets the track. An expedited appeal can be requested orally.5 ecfr.gov

A peer-to-peer is a payer courtesy. The reviewer’s credentials are a right

No federal rule entitles a commercial provider to a phone call with the plan’s physician. What the rules require is who does the reviewing, and that is the more useful demand.

In Medicare Advantage, a physician or appropriate health care professional with expertise in the relevant field — including knowledge of Medicare coverage criteria, and holding a current unrestricted license — must review the file before the plan issues an adverse medical-necessity organization determination.7 ecfr.gov On reconsideration, where the issue is medical necessity, the redetermination “must be made by a physician with expertise in the field of medicine that is appropriate for the services at issue.”7 ecfr.gov Neither provision requires the same specialty as the treating clinician.7 ecfr.gov

So take the peer-to-peer when it is offered pre-service or concurrently, where a live conversation can still change a level-of-care decision before the episode ends. Do not treat it as the appeal. Ask for the reviewer’s name, specialty and license status, put the answer in the file, and if the ASAM or level-of-care question was decided by someone with no addiction-medicine or psychiatric background, that fact belongs in the written appeal.

What actually moves a medical-necessity denial

Argue against the criteria set the payer used, not against the code.

You are entitled to see that criteria set. For mental health and substance use disorder benefits, the medical-necessity criteria “must be made available by the plan administrator… to any current or potential participant, beneficiary, or contracting provider upon request.”8 ecfr.gov That is a parity requirement and it names contracting providers directly. Separately, an ERISA denial notice must either state the internal rule relied on or offer it free of charge on request, and where the denial is based on medical necessity, must give the scientific or clinical judgment applying the plan’s terms to this patient’s circumstances — or offer that explanation free on request.5 ecfr.gov Request both. In writing. Every time.

Then build the packet around the criteria, element by element:

1. The criteria set, quoted. Name it — ASAM, MCG, InterQual, the plan’s own policy number and version.
2. The clinical record mapped to it. For each criterion, the chart entry, date and clinician that satisfies it. Not a narrative summary.
3. Risk documentation. Assessment scores, withdrawal scales, suicidality and self-harm history, prior failed attempts at a lower level of care with dates and outcomes.
4. The treating clinician’s letter. Signed, on letterhead, addressing the payer’s stated reason directly.
5. The regulatory hook. The specific paragraph the plan has to satisfy.

A reusable appeal letter structure

Eight blocks. Same order every time, so a reviewer can find each one without reading the whole thing.

1. Header block. Patient name, member ID, claim number, dates of service, CPT/HCPCS and revenue codes, billed amount, denial date, and the CARC/RARC exactly as they appear on the remittance.
2. One sentence naming the appeal. “This is a first-level appeal of a medical-necessity denial” — or a redetermination request, or an expedited pre-service appeal. Say which, and say the level.
3. The payer’s stated reason, quoted verbatim. Quote it. Do not paraphrase a reason you are about to dispute.
4. The standard you are being measured against. Name the criteria set and version, or the Medicare coverage requirement, and quote the specific element in dispute.
5. The facts, mapped to that standard. Numbered to match. Each with a chart date and a page reference into the enclosures.
6. The regulatory or contractual basis. The paragraph the plan or contractor must satisfy — reviewer qualifications, deference, the duty to explain the clinical judgment, a state prompt-pay or parity provision.
7. The specific relief requested. Overturn and pay $X on claim number Y. Not “please reconsider.”
8. Enclosure index. Numbered, with page counts.

Two lines to add near the top when they apply. If you are asking for expedited handling, state the clinical basis and who made the urgency determination. If a peer-to-peer already happened, name the reviewer, the date, and what was said.

Keep every deadline in a tickler tied to the receipt date, not the notice date, and count in calendar days. Both Medicare tracks presume you received the notice five days after it was dated,2 ecfr.gov7 ecfr.gov which means the five days you assume you have are already spent.