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name: pa-clinical-policy description: > Reasoning skill for prior authorization clinical policy evaluation. Use when the user asks about payer clinical criteria, step therapy requirements, medical necessity definitions, CMS LCD/NCD coverage rules, appeals documentation strategy, formulary tier implications, or FHIR Da Vinci PAS implementation guidance. Triggers include "prior auth policy", "step therapy", "medical necessity", "coverage determination", "LCD", "NCD", "formulary tier", "PA appeal", "peer-to-peer review", "Da Vinci PAS", "clinical criteria", "PA denial", "drug authorization", "utilization management". usage: Use when evaluating prior authorization clinical policies, coverage rules, or appeal strategies. version: 1.0.0 tags: [skill, category:reasoning, prior-authorization, clinical-policy, hcls]

Prior Authorization Clinical Policy Reasoning

Overview

Guide the agent through structured evaluation of prior authorization (PA) clinical policies, coverage determinations, step therapy protocols, and appeals processes. This skill encodes payer policy logic so the agent can assess whether a requested service meets authorization criteria, identify documentation gaps, and recommend appeal strategies.

Usage

• Invoke when evaluating whether a service meets prior authorization clinical criteria
• Use for step therapy evaluation, medical necessity assessment, or appeal strategy
• Activate for CMS LCD/NCD coverage rules or Da Vinci PAS implementation guidance

Core Concepts

Response Format

• Lead with the direct recommendation or classification (≤3 sentences)
• Structure as: recommendation → justification (citing specific criteria/thresholds) → caveats
• Use tables for comparisons; bullet points for criteria lists
• Omit background the user already knows — they asked the question
• Target: 200-400 words unless the user requests exhaustive detail The decision trees and frameworks in this skill are for internal reasoning only. Apply them to reach your conclusion, but do not reproduce them in your response. Present only the final recommendation with supporting evidence.

1. Prior Authorization Decision Framework

When a user asks about a PA decision, follow this sequence:

1. Identify the service type: drug (pharmacy benefit), procedure, DME, or imaging
2. Determine the payer: commercial, Medicare, Medicaid, or Medicare Advantage
3. Locate the applicable policy: formulary, LCD/NCD, or internal clinical criteria
4. Evaluate medical necessity: match diagnosis + clinical evidence to criteria
5. Check step therapy: confirm required prior treatments were attempted
6. Assess documentation completeness: verify all required supporting information
7. Recommend action: approve path, identify gaps, or outline appeal strategy

2. Clinical Criteria Structures

2.1 Medical Necessity Definition

Medical necessity requires ALL of the following:

1. Clinically appropriate: consistent with diagnosis, symptoms, and accepted standards of care
2. Not primarily for convenience: of the patient, provider, or payer
3. Most cost-effective level: among equally effective alternatives
4. Not experimental: FDA-approved or supported by peer-reviewed evidence
5. Expected to improve outcome: measurable clinical benefit anticipated

2.3 Diagnosis-Specific Criteria Examples

Condition	Requested Service	Required Criteria
Rheumatoid Arthritis	Biologic (TNF inhibitor)	Failure of ≥1 conventional DMARD (methotrexate) for ≥3 months
Multiple Sclerosis	Disease-modifying therapy	Confirmed MS diagnosis (McDonald criteria), relapse history
Chronic Pain	Opioid >90 MME/day	Pain management referral, urine drug screen, treatment agreement
Diabetes (Type 2)	GLP-1 receptor agonist	HbA1c ≥7% on metformin, or metformin contraindication documented
Cancer	PET/CT scan	Staging of newly diagnosed cancer or restaging after treatment
Sleep Apnea	CPAP device	AHI ≥5 on polysomnography, clinical symptoms documented

3. Step Therapy Requirements

3.1 Step Therapy Logic

Step therapy mandates that lower-cost or first-line treatments are tried before authorizing higher-cost alternatives. The general pattern:

Step 1: Generic / first-line therapy
  ↓ (documented failure, intolerance, or contraindication)
Step 2: Preferred brand / second-line therapy
  ↓ (documented failure, intolerance, or contraindication)
Step 3: Non-preferred / specialty therapy

3.2 Step Therapy Evaluation Rules

1. Adequate trial duration: each step must be tried for the clinically appropriate duration
   • Most oral medications: 30–90 days
   • Biologics: 12–16 weeks
   • Behavioral health: 8–12 weeks
2. Documented failure: objective evidence of inadequate response (lab values, symptom scores)
3. Intolerance: documented adverse effects that preclude continued use
4. Contraindication: clinical reason the step cannot be attempted (allergy, drug interaction, comorbidity)
5. Step skip exceptions: life-threatening conditions, prior step completed at another plan

3.3 Common Step Therapy Sequences

Drug Class	Step 1	Step 2	Step 3
Statins	Generic atorvastatin/rosuvastatin	Preferred brand statin	PCSK9 inhibitor
Antidepressants	Generic SSRI (sertraline, fluoxetine)	Generic SNRI (venlafaxine)	Brand atypical (Trintellix)
Biologics (RA)	Methotrexate + conventional DMARD	Preferred TNF inhibitor	Non-preferred biologic/JAK inhibitor
Diabetes	Metformin	Sulfonylurea or SGLT2	GLP-1 RA or insulin
Asthma	ICS (fluticasone)	ICS/LABA combination	Biologic (omalizumab, dupilumab)

4. CMS Coverage Determinations

4.1 NCD vs LCD

Attribute	NCD (National)	LCD (Local)
Issuer	CMS central	Medicare Administrative Contractor (MAC)
Scope	All Medicare nationwide	MAC jurisdiction (A/B or DME)
Override	Cannot be overridden locally	Must comply with any applicable NCD
Appeal path	ALJ → Medicare Appeals Council → Federal court	Redetermination → QIC → ALJ
Update frequency	Infrequent (years)	More frequent (annual review)

4.2 LCD Evaluation Checklist

When assessing whether a service is covered under an LCD:

• Identify the MAC jurisdiction for the provider's location
• Search the CMS Medicare Coverage Database for active LCDs
• Check the LCD's ICD-10 code list — is the patient's diagnosis included?
• Review the "Indications and Limitations" section for clinical criteria
• Verify the CPT/HCPCS code is listed as covered under the LCD
• Check for any associated billing article with documentation requirements
• Confirm no superseding NCD exists for the same service

5. Formulary Tier Structure

5.1 Formulary Exception Process

1. Standard exception: prescriber submits clinical rationale for non-formulary drug
2. Expedited exception: urgent clinical need, 24-hour turnaround required
3. Tier reduction: request lower cost-sharing based on medical necessity
4. Required documentation: letter of medical necessity, prior treatment history, lab results

6. Appeals Process

6.1 Appeal Levels (Commercial)

Level	Action	Timeline	Decision Maker
1	Internal appeal	30 days (standard), 72 hours (expedited)	Payer medical director
2	External review	45 days (standard), 72 hours (expedited)	Independent Review Organization (IRO)
3	State regulatory	Varies by state	Department of Insurance

6.2 Appeal Levels (Medicare Part C/D)

Level	Action	Timeline
1	Plan redetermination	7 days (expedited), 30 days (standard)
2	Independent Review Entity (IRE)	7 days (expedited), 30 days (standard)
3	Administrative Law Judge (ALJ)	Amount in controversy ≥$180 (2024)
4	Medicare Appeals Council	No minimum amount
5	Federal District Court	Amount in controversy ≥$1,760 (2024)

6.3 Peer-to-Peer Review Best Practices

When preparing for a peer-to-peer review with the payer medical director:

1. Know the specific denial reason: request the denial letter and clinical policy cited
2. Prepare clinical evidence: relevant labs, imaging, treatment history, specialist notes
3. Reference guidelines: cite society guidelines (ACR, NCCN, AAN) supporting the request
4. Document prior treatments: list all failed/tried therapies with dates and outcomes
5. Articulate medical necessity: explain why this specific service is required for this patient
6. Note urgency: if delay poses clinical risk, document the time-sensitive nature

6.4 Documentation Checklist for Appeals

• Copy of the denial letter with specific reason codes
• Letter of medical necessity from treating physician
• Relevant clinical notes (last 6–12 months)
• Lab results supporting the diagnosis and treatment need
• Prior treatment history with dates, doses, and outcomes
• Society guideline excerpts supporting the requested service
• Peer-reviewed literature (if off-label or emerging therapy)
• Patient statement (if relevant to functional impact)

7. FHIR Da Vinci PAS Implementation

7.1 Overview

The Da Vinci Prior Authorization Support (PAS) Implementation Guide defines a FHIR-based workflow for submitting and tracking prior authorization requests. CMS mandates payer support by 2026.

7.2 PAS Workflow Sequence

1. Provider EHR constructs a PAS Bundle with Claim + supporting resources
2. EHR submits $submit operation to payer's PAS endpoint
3. Payer returns ClaimResponse with disposition: approved, denied, or pended
4. If pended, payer may request additional info via CommunicationRequest
5. Provider submits updated Bundle with requested documentation
6. Payer issues final ClaimResponse
7. Provider queries $inquire operation for status updates

When NOT to Use This Skill

• Making coverage determinations for individual patients (requires licensed clinician)
• When payer-specific contracts override published clinical policies
• Adjudicating appeals that require medical record review

When to Escalate to a Human Expert

• Peer-to-peer review preparation (needs treating physician)
• When denial involves experimental/investigational determination
• When state Medicaid rules conflict with commercial payer policies

8. Common Mistakes

• Wrong: Assuming all payers use the same clinical criteria for a given service Right: Always check the specific payer's published clinical policy before submitting a PA request Why: Each payer maintains independent policies; criteria that work for one payer may not apply to another

• Wrong: Skipping step therapy documentation when the patient tried a drug at a prior plan Right: Document all prior treatments with dates, doses, duration, and outcomes — even from previous plans Why: Without documented evidence of prior steps, the payer will deny regardless of actual treatment history

• Wrong: Submitting appeals without addressing the specific denial reason code or cited criteria Right: Reference the exact denial reason and provide evidence directly addressing each unmet criterion Why: Generic appeals that don't target the specific denial rationale are almost always upheld

• Wrong: Applying an LCD from one MAC jurisdiction to a provider in a different MAC's territory Right: Identify the correct MAC jurisdiction for the provider's location and use that MAC's LCD Why: LCDs are jurisdiction-specific; coverage rules from one MAC have no authority in another

• Wrong: Treating LCDs and NCDs as equivalent or interchangeable Right: Always check for an applicable NCD first — NCDs take precedence and cannot be overridden by LCDs Why: An LCD cannot contradict or override a National Coverage Determination

• Wrong: Missing formulary exception deadlines, especially for expedited requests Right: Track and meet all turnaround requirements — 24 hours for expedited exceptions Why: Missed deadlines result in automatic denials and delayed patient access to needed medications

• Wrong: Conducting peer-to-peer reviews without citing published clinical guidelines Right: Reference specific society guidelines (ACR, NCCN, AAN) that support the requested service Why: Peer-to-peer reviews are significantly more effective when backed by authoritative guideline citations

• Wrong: Attaching clinical documentation as unstructured PDFs in Da Vinci PAS bundles Right: Structure clinical documentation in the supportingInfo field using proper FHIR resource references Why: Unstructured attachments cannot be processed by automated adjudication systems, causing delays

• Wrong: Applying commercial appeal timelines and processes to Medicare PA requests Right: Use Medicare-specific appeal levels and timelines (redetermination → IRE → ALJ → MAC → Federal court) Why: Medicare has distinct appeal levels, timelines, and amount-in-controversy thresholds

• Wrong: Failing to track PA expiration dates after authorization is granted Right: Monitor authorization validity periods and reauthorize before expiration if services are ongoing Why: Services rendered after PA expiration require new authorization — retroactive approval is rarely granted

9. Decision Tree: PA Request Evaluation

Is the service on the payer's PA-required list?
├── NO → No PA needed; proceed with service
└── YES
    ├── Is there an applicable NCD?
    │   ├── YES → Does the request meet NCD criteria?
    │   │   ├── YES → Approve (document NCD compliance)
    │   │   └── NO → Deny (cite NCD; appeal to ALJ if Medicare)
    │   └── NO → Check for LCD or plan-specific policy
    │       ├── LCD exists → Evaluate LCD criteria
    │       └── Plan policy exists → Evaluate plan criteria
    │           ├── Medical necessity met?
    │           │   ├── YES → Check step therapy
    │           │   │   ├── Step therapy satisfied → Approve
    │           │   │   └── Step therapy NOT satisfied
    │           │   │       ├── Exception applies? → Approve with exception
    │           │   │       └── No exception → Deny (cite step therapy)
    │           │   └── NO → Deny (cite medical necessity)
    │           └── Documentation incomplete?
    │               └── Pend for additional information

10. Quick Reference: Denial Reason Categories

Category	CARC Code Range	Example	Recommended Action
Medical necessity not met	50, 56	Diagnosis does not support service	Appeal with clinical evidence
Step therapy not completed	149	Required prior drug not tried	Document prior treatments
Not a covered benefit	96, 97	Service excluded from plan	Formulary exception or plan change
Documentation insufficient	16, 252	Missing clinical notes	Resubmit with complete records
Experimental/investigational	56	Off-label use not approved	Cite peer-reviewed evidence
Out of network	151	Provider not in network	Network exception or referral
Duplicate authorization	18	PA already exists for service	Verify existing PA status

11. PA Turnaround Time Requirements

Request Type	Commercial (typical)	Medicare Part C	Medicare Part D
Standard (non-urgent)	15 calendar days	14 calendar days	72 hours (standard)
Expedited (urgent)	72 hours	72 hours	24 hours
Retrospective	30 calendar days	30 calendar days	N/A
Extension (pend for info)	+14 days (one extension)	+14 days	+14 days

Urgency Determination Rules

A request qualifies as expedited when:

1. Applying standard timeframe could seriously jeopardize the patient's life or health
2. Applying standard timeframe could jeopardize the patient's ability to regain maximum function
3. A physician indicates the request is urgent (physician attestation)
4. The patient is currently undergoing treatment that would be interrupted

12. Quantity Limits and Site-of-Care Policies

12.1 Quantity Limit Structures

Limit Type	Description	Example
Per-fill limit	Maximum units per prescription fill	30-day supply for controlled substances
Per-period limit	Maximum units over a time period	9 fills per year for triptan medications
Lifetime limit	Maximum total units ever	Gene therapy — single administration
Diagnosis-based limit	Quantity varies by condition	Higher opioid limits for cancer pain

12.2 Site-of-Care Optimization

Payers increasingly require lower-cost sites for infusion and injection therapies:

Is the drug available for home infusion?
├── YES → Home infusion preferred (lowest cost)
│   ├── Patient clinically stable? → Approve home infusion
│   └── Patient requires monitoring? → Approve outpatient infusion center
└── NO → Is outpatient infusion center available?
    ├── YES → Outpatient preferred over hospital outpatient
    └── NO → Hospital outpatient department approved

13. Regulatory Timeline: Key PA Reform Dates

Date	Regulation	Impact
Jan 2024	CMS Interoperability Rule (CMS-0057-F) finalized	Payers must implement FHIR PAS API
Jan 2026	FHIR PAS API mandate effective	Payers must accept electronic PA via Da Vinci PAS
Jan 2026	PA decision transparency	Payers must provide specific denial reasons and applicable criteria

Gold Carding Programs

Several states require payers to exempt providers from PA if they demonstrate ≥90% approval rate for a specific service over 12 months. Exemption lasts 12 months, subject to audit, and is revoked if approval rate drops below threshold.