📋 Authorizations and Appeals

           A Comprehensive Resource Guide for Healthcare Billing Professionals


This resource guide is a practical reference for billing staff, medical coders, and revenue cycle teams who manage prior authorizations and claims appeals. Use it to standardize workflows, reduce preventable denials, and respond to payer decisions with clear documentation and timely follow-up. While payer rules vary, the steps and best practices below provide a reliable framework for day-to-day operations.








📝 Prior Authorizations


What Are Prior Authorizations?


Prior authorizations (PAs) are advance approvals from a payer confirming that a specific service, procedure, medication, or item meets coverage rules and medical necessity criteria before it is provided. They are commonly used to manage utilization, confirm benefit eligibility for certain services, and reduce inappropriate or non-covered care. Approval typically results in an authorization number and an effective date range that must align with the billed claim.


When Are They Required?


  • Elective surgeries
  • High-cost imaging (MRI, CT, PET scans)
  • Specialty medications
  • Durable medical equipment (DME)
  • Inpatient admissions
  • Certain outpatient procedures


How to Submit Authorizations


Most payers accept authorizations through multiple channels. Use the method that best supports documentation, turnaround time, and tracking for your team.


  • Phone: Call the payer’s authorization line and be prepared with patient demographics, member ID, ordering provider details, requested CPT/HCPCS and ICD-10 codes, and supporting clinical notes. Document the call date/time, reference or call confirmation number, and the representative’s name for your tracking log.
  • Online Portal: Many payers offer web-based submission with faster turnaround, real-time status updates, and the ability to upload supporting documents (orders, notes, test results). Save screenshots or portal confirmations and record the submission ID in your tracking system.
  • Fax: Use payer-specific forms and include a cover sheet with patient demographics, procedure details, ordering provider information, and all required clinical documentation. Keep the fax confirmation receipt and file it with the authorization packet for audit support.


Common Payer Requirements


  • Medical necessity documentation
  • Physician orders
  • Clinical notes
  • Relevant test results
  • Previous treatment history
  • ICD-10 diagnosis codes
  • CPT/HCPCS procedure codes


Tips for Avoiding Denials


  1. Verify benefits and authorization requirements before scheduling (including site-of-service rules and network status).
  2. Submit requests with adequate lead time—plan for at least 5–10 business days for routine requests unless the payer states otherwise.
  3. Confirm all required documentation is included (orders, clinical rationale, test results, and prior treatment history).
  4. Use correct and specific ICD-10 and CPT/HCPCS codes that match the documentation and payer policy criteria.
  5. Follow up on pending requests and document every contact, reference number, and status update.
  6. Maintain an authorization tracking log with effective dates and expiration dates to prevent billing outside the approved window.


✅ Authorization Best Practices


Critical Timelines


Processing times vary by payer and plan type, but common benchmarks include routine requests in 5–10 business days, urgent requests within 72 hours, and emergency situations handled same-day or as soon as clinically feasible. Always confirm payer-specific definitions of “urgent” and required documentation, as missing elements can reset the clock or trigger an administrative denial.


Documentation Requirements


  • Complete patient demographics (including member ID and group number)
  • Detailed clinical rationale supporting medical necessity
  • Supporting diagnostic results (imaging reports, labs, prior evaluations)
  • Physician signature and credentials (as required by payer)
  • Dates of service (requested/anticipated) and service frequency/duration when applicable
  • Place of service (facility vs. outpatient, home, etc.)


Tracking Methods


Use a centralized spreadsheet or authorization software to track every request from submission through claim payment. At minimum, include columns for: patient name, date requested, payer, procedure/service, status, authorization number, expiration date, and follow-up date. Standardizing these fields helps prevent missed deadlines, supports audits, and makes it easier to identify payer bottlenecks or recurring denial patterns.


Expired or Retroactive Authorizations


If an authorization is nearing expiration, request an extension or submit a new authorization before the service date whenever possible. Retroactive authorizations are rarely approved, but they may be considered when supported by documentation of an emergency, urgent clinical need, or other extenuating circumstances; include a clear timeline and supporting records. If the payer denies retroactive approval, reference the payer’s published policy language and any applicable contract terms in the appeal.


⚠️ Claims Denials & Appeals


Types of Denials


  • Administrative Denials: Missing information, incorrect patient ID, duplicate claims, or timely filing issues. These are often the easiest to overturn by correcting the claim, attaching required documentation, and resubmitting within payer rules.
  • Clinical Denials: Medical necessity not established, experimental/investigational treatment, or lack of prior authorization. These typically require clinical documentation, policy-based justification, and a formal appeal (and may benefit from peer-to-peer review).
  • Technical Denials: Coding errors, unbundling issues, modifier problems, or mismatched diagnosis/procedure logic. Correct the coding, include a brief explanation when appropriate, and resubmit or appeal based on payer guidance.


Reading an EOB or Remittance Advice


An Explanation of Benefits (EOB) or remittance advice explains how the payer processed the claim and why any portion was adjusted or denied. Key sections to review include: claim number, patient name, date(s) of service, billed amount, allowed amount, adjustment codes, denial reason codes, and remark messages. Cross-reference CARC (Claim Adjustment Reason Codes) and RARC (Remittance Advice Remark Codes) to confirm the payer’s stated rationale and to determine whether the next step is a corrected claim, reconsideration, or formal appeal.


Grounds for Appeal


  • Services were medically necessary
  • Authorization was obtained (or not required per policy/benefits)
  • Coding was correct and supported by documentation
  • Payer error in processing or misapplication of policy
  • Timely filing requirements were met (with proof)
  • Coverage policy supports the service when criteria are met


📤 The Appeals Process


Step-by-Step Appeal Guidance


  • First-Level Appeal: Submit within the payer deadline (often 180 days for commercial plans and 120 days for Medicare). Include an appeal letter, the original claim and supporting documentation, clinical notes supporting medical necessity, relevant payer policies, and any authorization documentation (approval number, dates, and submission proof).
  • Second-Level Appeal: If the first appeal is denied, escalate within the specified timeframe (commonly 60 days). Provide additional clinical evidence, consider a peer-to-peer review when available, and reference specific policy language and criteria that support coverage.
  • External Appeal: For many commercial plans, request an Independent Review Organization (IRO) review; for Medicare, follow the process that may involve a Qualified Independent Contractor (QIC). Include all prior correspondence, decisions, and the complete clinical and billing record supporting your position.



Deadlines and Timelines by Payer Type

Payer Type First Appeal Deadline Second Appeal Deadline External Review
Medicare 120 days 180 days QIC review available
Medicaid Varies by state (60–90 days) Varies by state State fair hearing
Commercial 180 days typical 60 days from first denial IRO within 4 months
Medicare Advantage 60 days 60 days IRO available

Required Documentation


  • Copy of denial letter/EOB or remittance advice
  • Completed appeal form (if required by payer)
  • Detailed appeal letter
  • Original claim with all attachments submitted
  • Clinical documentation (progress notes, test results, treatment plans)
  • Relevant medical literature or guidelines (when applicable)
  • Authorization documentation (approval number, dates, submission proof), if applicable
  • Physician statement/signature, if needed


Writing an Effective Appeal Letter


  1. Use professional letterhead (or organization header) and include the date and payer appeal address/fax/portal destination.
  2. Include patient and claim identifiers (patient name, DOB, member ID, claim number, date(s) of service, provider NPI, and billed codes).
  3. Clearly state that you are appealing the denial and specify the service(s) and amount(s) in dispute.
  4. Cite the specific denial reason(s) and any CARC/RARC or policy references provided by the payer.
  5. Provide a point-by-point rebuttal supported by documentation (clinical notes, test results, orders, and timelines).
  6. Reference payer policies and applicable medical guidelines that support coverage and medical necessity.
  7. Request a specific action (overturn the denial and process payment) and include direct contact information for follow-up.


📚 Key Terms & Definitions


Medical Necessity: Healthcare services that are appropriate for diagnosis and/or treatment, meet accepted standards of care, and are not primarily for the convenience of the patient or provider.


Prior Authorization: Advance approval from a payer before service delivery confirming that coverage criteria are met.


Peer-to-Peer Review: A phone discussion between the requesting physician and the payer’s medical director (or designee) to review clinical rationale and coverage criteria.


Concurrent Review: Ongoing review during an inpatient stay to assess continued medical necessity and appropriate level of care.


Retrospective Review: Review performed after services are rendered to determine whether they were medically necessary and covered.


IRO (Independent Review Organization): An external entity that reviews denied services/claims impartially when internal appeals are exhausted or when external review is permitted.


EOB (Explanation of Benefits): A statement describing how a claim was processed, what was paid, adjustments applied, and the patient’s responsibility.


CARC (Claim Adjustment Reason Code): Standardized codes that explain why a claim line was adjusted or denied.


RARC (Remittance Advice Remark Code): Supplemental codes that provide additional detail about claim processing or required actions.


Timely Filing: The deadline by which claims must be submitted to the payer, which varies by payer and contract.



Clean Claim: A claim submitted with all required information and documentation, free of errors or omissions that would delay processing.


💡 Quick Reference Tips


Common Denial Codes

Code Description Action
CO-16 Claim lacks information Resubmit with missing data
CO-50 Non-covered service Appeal with medical necessity documentation
CO-96 Non-covered charge Review coverage policy, appeal if appropriate
CO-197 Precertification absent Submit retroactive auth request or appeal
CO-29 Timely filing limit Appeal with proof of timely submission

Escalation Strategies


  1. Start with payer customer service to confirm denial rationale, required corrections, and the correct submission pathway.
  2. Request a supervisor or escalation team if the issue is unresolved or the explanation conflicts with policy/contract terms.
  3. Initiate the formal appeal process and submit a complete, well-organized appeal packet within deadlines.
  4. Involve the provider relations representative for recurring issues, systemic processing errors, or contract interpretation concerns.
  5. Consider peer-to-peer review for clinical denials when the payer offers it and the case hinges on medical necessity criteria.
  6. Engage the payer medical director for complex cases requiring clinical nuance or policy interpretation.
  7. Pursue external review when internal appeals are exhausted and the case meets eligibility requirements.


When to Involve Physician or Clinical Staff


  • Clinical denials requiring medical necessity justification
  • Peer-to-peer review requests
  • Complex cases needing detailed clinical rationale and documentation support
  • Experimental/investigational treatment denials
  • Appeals requiring a physician signature, attestation, or statement
  • Authorization requests for high-risk procedures or services with strict clinical criteria



Successful authorization and appeals management depends on attention to detail, thorough documentation, and consistent follow-through. Use this guide as an ongoing reference to standardize your workflow, reduce avoidable denials, and strengthen appeal outcomes. Always confirm payer-specific policies, deadlines, and submission requirements, and update internal processes as payer rules change.