ACA Marketplace · Medicaid · Medicare

Ambetter denied your claim: how to appeal

Centene operates one of the largest Medicaid footprints in the U.S. and sells ACA marketplace coverage under the Ambetter brand. Marketplace plans drew elevated regulator and journalist scrutiny in 2024 for higher-than-average denial rates on in-network claims, and Centene-managed Medicaid lines vary plan-by-plan by state.

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Centene / Ambetter reported claim denial rates, by state

In-network denial rate each Centene / Ambetter marketplace issuer reported to CMS (Transparency in Coverage PUF; two-year lag; includes administrative denials). Click a state for the full report card.

Centene / Ambetter denial rate, every state, three years →

All insurers and states →

Quick answer

If Centene / Ambetter denied a claim or service, you can appeal, and the plan must give you its file and the criteria it used. Filing windows by plan type: at least 180 days (insured and Marketplace plans); 60 days from the notice (Medicaid managed care); 65 days from the notice (Medicare Advantage). The date printed on your denial notice controls; it can only be later than these floors, never earlier.

At a glance

Centene / Ambetter appeals: the rule, the deadline and the next level, by plan type

Which row applies depends on the plan you hold, not on Centene / Ambetter's brand. Your ID card, the Summary Plan Description and the denial letter say which.

Plan type	Rule that governs	File your appeal within	The plan must answer	If the plan says no again
Fully insured employer, individual or Marketplace plan The carrier holds the risk and is licensed in your state. Small employers and almost all individual and HealthCare.gov plans.	45 CFR 147.136 (Public Health Service Act § 2719), which applies the 29 CFR 2560.503-1 procedures and adds state external review; state insurance law on top.	At least 180 days from the denial (45 CFR 147.136(b); 29 CFR 2560.503-1(h)(3)(i)).	Urgent care: 72 hours. Pre-service: 30 days. Post-service: 60 days. Prior-authorization decisions by Marketplace issuers from 2026: 72 hours expedited, 7 calendar days standard (CMS-0057-F).	External review through your state's process, or the federal process where the state has none, generally within 4 months of the final internal denial (45 CFR 147.136(c), (d)). The state insurance department and its Consumer Assistance Program take complaints.
Medicaid managed care plan A Medicaid plan run by the carrier under a state contract. The card says Medicaid, Medi-Cal, STAR, HealthChoice or your state's programme name.	42 CFR Part 438, Subpart F (plan appeals) and 42 CFR Part 431, Subpart E (state fair hearings).	60 calendar days from the date on the notice of adverse benefit determination to request the plan's appeal (42 CFR 438.402(c)(2)(ii)). State fair hearing: within 120 calendar days of the plan's appeal decision (§ 438.408(f)(2)).	Standard appeal: 30 calendar days. Expedited: 72 hours (42 CFR 438.408(b)).	A state fair hearing after the plan's single level of appeal (§ 438.402(b)); some states add an external medical review. Benefits continue during the appeal if you ask within 10 calendar days of the notice (§ 438.420).
Medicare Advantage (Part C) A private plan that replaces Original Medicare. The card says Medicare Advantage, HMO, PPO or PFFS.	42 CFR Part 422, Subpart M (§§ 422.560 to 422.634). Coverage decisions must follow Original Medicare rules (42 CFR 422.101).	65 calendar days from the date on the denial notice to request the plan's reconsideration (42 CFR 422.582, as amended effective 1 January 2025).	Expedited: 72 hours. Standard pre-service: 30 days (7 days for Part B drugs). Payment: 60 days (42 CFR 422.590).	If the plan does not fully reverse itself it must send the case to the Independent Review Entity on its own (42 CFR 422.592); then an ALJ hearing when the amount in controversy meets the annual threshold, the Medicare Appeals Council and federal court. State external review does not apply.

Fully insured employer, individual or Marketplace plan

What you can demand. The plan must give you the claim file, the criteria it applied and any new evidence or rationale before the final decision, free of charge (45 CFR 147.136(b)(2)(ii)(C); 29 CFR 2560.503-1(h)(2)(iii)).

How to open the appeal. Cite 45 CFR 147.136 and 29 CFR 2560.503-1: request the claim file and the criteria, note the decision clocks, and name the state external-review right.

Medicaid managed care plan

What you can demand. Free copies of the case file, medical records and the criteria used, before and during the appeal (42 CFR 438.406(b)(5)). Children under 21 have EPSDT rights to medically necessary care (42 U.S.C. 1396d(r)(5)).

How to open the appeal. Cite 42 CFR 438.402 and 438.406(b)(5): request the case file and the criteria, ask for continued benefits within 10 days, and reserve the state fair hearing.

Medicare Advantage (Part C)

What you can demand. The plan may not apply internal criteria that are more restrictive than Medicare's national and local coverage determinations, and must decide medical necessity on your individual circumstances (42 CFR 422.101(b), (c)). You can ask for the case file and the criteria used.

How to open the appeal. Cite 42 CFR 422.582 and 422.101(c): the plan must decide on your individual circumstances under Medicare coverage rules, and must forward an unfavorable reconsideration to the IRE itself.

Reported denial rates

In the CMS Transparency in Coverage data for plan year 2026 (2024 claims), the 27 Centene / Ambetter-family Marketplace issuer filings across 21 states reported in-network claim denial rates from 13.7% to 36.3% (median 18.8%). Issuer-level, self-reported, HealthCare.gov plans only; a denial includes duplicate and administrative denials.

Centene / Ambetter denial rate: every state, three years →

Primary sources for this table

Windows are federal floors or the rule as written; the denial notice controls. Reviewed 13 September 2026. General information, not legal advice; Apellica is not a law firm.

Patterns we see on Ambetter denials

ACA marketplace in-network denials

Ambetter marketplace plans have been documented denying in-network medical claims at rates above the marketplace average. Federal ACA rules guarantee internal appeal plus external review via an Independent Review Organization (IRO), both are no-cost to the member.

Narrow networks driving care-access denials

Ambetter HMO products often run narrower networks than the local competition. Network-adequacy challenges (state DOI complaints citing inadequate specialist access) can convert an out-of-network denial into in-network coverage.

Medicaid managed care fair hearings

Centene-managed Medicaid plans (Sunshine Health, Buckeye, Peach State, etc.) operate under each state's Medicaid rules. After plan-level appeal, members have the right to a state fair hearing, a binding administrative process with strong reversal history.

Appeal levels available

Marketplace: internal appeal then federal external review (IRO). Medicaid: plan appeal then state fair hearing. Medicare Advantage: federal 5-level ladder.

Filing deadlines

180 days from denial for marketplace internal appeals; 4 months / 120 days for federal external review. Medicaid fair-hearing deadlines vary by state, often as short as 90-120 days.

How we file Ambetter appeals

We confirm the specific Centene subsidiary (Ambetter, Sunshine Health, Wellcare, etc.) before filing, because procedural rules and the supervising regulator change with the line of business.

Ambetter denials: the questions people ask

How long do I have to appeal a Ambetter denial?

180 days from denial for marketplace internal appeals; 4 months / 120 days for federal external review. Medicaid fair-hearing deadlines vary by state, often as short as 90-120 days. Count from the date on the denial letter, not the date you opened it.

Where do I send a Ambetter appeal?

The appeal address, fax number or portal for your specific plan is printed on your denial letter, usually under a heading like "Your right to appeal" or "How to request a review". We deliberately do not publish one address per carrier: Ambetter routes appeals differently by employer group, region, product line and appeal level, and sending it to the wrong place can cost you the deadline. If the letter does not state where to send it, that omission is itself worth raising in the appeal, and the member number on your card reaches someone who must tell you.

What should a Ambetter appeal letter include?

The member and claim numbers, the exact denial reason quoted from the letter, the clinical records that answer that specific reason, and a request in writing for the criteria the decision was based on and a copy of the claim file. Appeals succeed on what you attach more than on how strongly you argue, because the first reviewer often never saw the full chart.

What happens if Ambetter denies the appeal again?

Marketplace: internal appeal then federal external review (IRO). Medicaid: plan appeal then state fair hearing. Medicare Advantage: federal 5-level ladder. After a final internal denial, external review by an independent organisation is a separate lane, it is free to you, and the decision binds the plan. Which external review applies depends on whether your plan is employer self-funded, state-regulated, Medicare or Medicaid.

Ambetter appeal guides by denial type

What Ambetter tends to cite for each kind of denial, the rule that controls it, and what the appeal has to say.

Free appeal letter templates by denial type →External review after Ambetter upholds the denial →

Denied by Ambetter? Let's appeal it.

Two-minute micro intake. We confirm fit and reply within one business day. No card at intake. You only pay if the carrier reverses the denial.

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Disclaimer: information shown is general guidance, not legal advice or a guarantee of outcome. Individual case outcomes depend on documentation, timing, and the specific terms of your plan.