What is a denial appeal?
A denial appeal is the formal challenge a hospital sends to a health plan asking it to review and pay a denied item or claim. Denial is the Brazilian term for a total or partial claim denial. The TISS standard (Brazil's mandatory standard for health data exchange) is issued by the National Supplementary Health Agency (ANS, Brazil's health plan regulator). Its Organizational Component defines the appeal as the process a provider uses to contest denials of one or more procedures or items in a claim [2].
The denial arrives in the claim analysis statement (demonstrativo de análise de conta, similar to a US remittance advice), which lists, for each reviewed claim form, the denied procedures and items [2]. Each denial carries a reason code from table 38 of TUSS (Unified Terminology for Supplementary Health, the TISS code sets), such as 3209, duplicate billing of a procedure or item [4]. The full picture is in the guide Denial.
The appeal is how initial denials turn back into revenue. A denial not contested within the deadline tends to become accepted denial, that is, a final loss.
The denial appeal in the TISS standard: four messages
The denial appeal must be exchanged electronically between health plans and providers, alongside claims submission, the authorization attachments batch, admission or discharge notices and remittance statements (item 33 of Organizational Component 202609) [2]. The process has four messages [2]:
| Message | Sent by | Purpose |
|---|---|---|
| Denial appeal | Hospital → health plan | Contests a denial applied to the claim |
| Appeal receipt | Health plan → hospital | Returns the protocol number that proves receipt |
| Status request | Hospital → health plan | Asks for the response to an appeal already sent |
| Appeal response | Health plan → hospital | Upholds the appeal or not; if still under review, sends a new protocol number |
For the hospital, the protocol number is the key piece: it proves the appeal was received [2] and is the date reference for chasing the response within the contract deadline. An appeal without a protocol number is hard to follow up. The standard is explained in the guide TISS standard.
The fields of the appeal message are defined in the TISS Content and Structure Component (version 202511 as of September 2026) [3]. In practice, the billing system builds the appeal from the statement, identifying the patient, the performing provider and the contested items, with the amount appealed and the justification for each. Some health plans also accept appeals typed into their own portals; even then, the appeal must follow the standard.
What is the deadline to appeal a denial?
The deadline is the one in the contract with the health plan. RN 503/2022 (ANS Normative Resolution 503/2022) does not set a number of days, but requires the contract to provide three deadlines: for the hospital to contest the denial, for the health plan to respond and for the health plan to pay when the denial is reversed (art. 14) [1].
The most objective rule is parity: the appeal deadline must equal the health plan's response deadline (art. 14, sole paragraph) [1]. If the hospital has 30 days to appeal, the health plan has 30 days to respond (illustrative example). Unequal deadlines in the contract fall outside the rule. Details are in the guide Appeal deadlines, and the contract review in the guide RN 503/2022: what the payer contract must say.
Article 5 of RN 503 forbids the health plan from creating rules that block the hospital's access to audit routines and denial justifications, or that block the appeal itself (items V and VI) [1]. The sole paragraph adds a condition: these prohibitions apply only if billing is submitted in the current TISS version [1]. A claim outside the standard weakens the very right to appeal.
How to file a denial appeal, step by step
An effective appeal starts before the justification is written: with triage of what is worth contesting and the right evidence for each reason.
- Read the claim analysis statement. Import the statement file into the system and sort denials by health plan, reason (table 38 code), amount and date received.
- Check each health plan's deadline. Record the appeal deadline set in the contract and prioritize by due date and amount.
- Triage: valid or improper? A valid denial, caused by a hospital error, is fixed at the source and, if the contract allows, rebilled; it is not appealed. An improper denial goes to appeal.
- Gather the evidence. Each reason calls for a specific document (see the table below). A justification without evidence tends to be rejected.
- Submit the appeal in the TISS standard, item by item, and keep the protocol number [2].
- Track the response and the payment. Send a status request if the response deadline passes [2]. If the denial is reversed, confirm payment within the contract deadline [1].
The appeal does not end at submission: it closes only when the reversed amount appears in the payment statement and is reconciled. This control is covered in the guide Remittance statements.
What evidence to attach for each type of denial?
The evidence depends on the denial reason. The split into administrative, clinical and across-the-board denials is a market convention, not an ANS definition, but it shows who handles each one and what document supports the appeal. The types are detailed in the guide Types of denials.
| Denial type | Example reasons | Evidence that supports the appeal | Who prepares it |
|---|---|---|---|
| Administrative: registration | Invalid member ID (table 38 code 1001) [4], member inactive on the date | Eligibility check from the date of service; copy of the member card | Billing and front desk |
| Administrative: authorization | Procedure without authorization; expired authorization code (senha); days beyond those authorized | Authorization code and date; extension request with protocol number; emergency record | Authorization team |
| Administrative: billing | Duplicate billing (code 3209) [4]; mismatched TUSS code; price outside the fee schedule | Claim forms showing no duplication; fee schedule and contract clause; current TUSS version | Billing |
| Clinical: medical necessity | Supplies or drugs above the expected amount; inpatient day without justification | Orders, nursing administration records, progress notes, operative report, attending physician's report | Physician and nurse auditors |
| Clinical: OPME (implants and special materials) | Material not authorized or not matching | OPME authorization, invoice, traceability labels, operative report | Audit and supply chain |
| Across-the-board | Percentage cut without item-level review | Contract clause listing denial scenarios; showing the reason is not covered | Contract management and legal |
For clinical denials, the opinion must come from a professional with the authority to issue it. Cofen Resolution 720/2023 (Federal Nursing Council) lists denial appeals among the activities of the nurse auditor, with the nursing license number on the opinions [7]. The rules for each professional are in the guides Physician audit and Nursing audit.
Ready-to-use template: the appeal structure by denial type
The template below is a structure for writing the justification, not the TISS form. Submission fields come from the system and the standard's message; the justification text is what the hospital controls. A good justification has four parts:
- Identification: health plan, batch number, claim form number, patient, date of service, contested item, denial reason code and amount appealed.
- Fact: what was done, when and why, in one or two sentences.
- Basis: the rule that supports the charge (contract clause, authorization, fee schedule, TUSS version or regulation).
- Evidence and request: the attached documents and the request to reverse and pay the amount within the contract deadline.
Sample justifications (illustrative text, adapt to the case and the contract):
| Denial reason | Template justification |
|---|---|
| No authorization | “Procedure [TUSS code] was authorized on [date], code [number], valid until [date], and performed on [date], within its validity. The authorization is attached. We request reversal and payment of BRL [amount].” |
| Expired authorization during an inpatient stay | “The extension was requested on [date], protocol [number], before the authorization expired. The length of stay is justified in the physician progress notes of [dates], attached. We request payment of the [n] denied days.” |
| Duplicate billing | “The items billed on claim forms [numbers] refer to separate encounters on [dates and times], as shown in the attached records. There is no duplicate billing. We request reversal.” |
| Price outside the fee schedule | “The amount billed follows clause [number] of the contract, which adopts [schedule and edition] with [factor]. The clause and calculation are attached. We request payment of the BRL [amount] difference.” |
| Supplies above the expected amount | “The quantity of [item] is recorded in the orders and nursing administration records of [dates], with the clinical justification in the progress notes, attached. We request full reversal.” |
| Across-the-board denial | “The [percentage] denial on [group of items] gives no item-level reason and does not match the denial scenarios in clause [number] of the contract, as required by article 14 of RN 503/2022. We request reversal and an item-by-item justification.” |
Two rules apply in every case: one justification per item, specific to the reason given, and no generic text such as “procedure performed as ordered.” The full template to download is in the CTA at the end of this guide.
Can a health plan deny a procedure it authorized?
RN 503/2022 does not address this case. CFM Resolution 2,448/2025 (Federal Council of Medicine), which regulates medical auditing, forbids the physician auditor from denying a procedure that was previously authorized and verifiably performed [5]. In March 2026, however, the CFM reported that health plan associations had obtained, in federal court, the suspension of some articles of the resolution, including this prohibition [6]. The resolution text published by the CFM, accessed on October 17, 2026, still marks articles as suspended in case 1017752-74.2026.4.01.3400 [5].
ANS Public Consultation 170/2026 proposes a similar rule for contracts: a procedure that was authorized and performed would not be denied if the claim follows the contract and no technical disagreement is identified in an audit [9]. As of October 17, 2026, the final rule had not been published [9].
Meanwhile, a denial of an authorized procedure is still contested with the authorization itself, the record of care and the contract clauses. The authorization is the hospital's strongest evidence in that appeal.
What we see in operations
At Accrua, an appeal starts with the remittance statement. Agents reconcile the health plan's response claim line by claim line, sort each denied item by its TUSS table 38 code and track the appeal deadline set in the contract. For each item, they prepare a draft appeal with the evidence that health plan asks for on that denial reason: an excerpt of the medical record, the authorization, a contract clause or the current price table.
The decision to appeal, accept the denial or drop the appeal always belongs to a person. The biller or auditor receives the case already assembled, with the source of every argument, and each choice is logged with who made it, on what basis and when. After the appeal is filed, agents follow the response and the payment of the reversed amount through to reconciliation.
We also flag what should not be appealed. When a denial is valid, the fix belongs at the source: the item master, charge entry or the authorization rule. The outcome of every appeal, upheld or not, goes back into the review of that health plan's next claims.
Where to start
- Build a deadline table with each health plan's appeal, response and payment deadlines, taken from the contracts.
- Import the statements and classify denials by table 38 code, amount and deadline.
- Standardize the justification using the four-part structure and the examples by reason in this guide.
- Define who proves what: billing for administrative denials, physician and nurse auditors for clinical ones.
- Track the reversal rate and payment time of appeals, by health plan and reason, every month.