Prior Authorization: Which Drugs and Procedures Get Denied Most (and Why)

The Prior Authorization Burden: Current Scale

The AMA's 2024 Prior Authorization Physician Survey quantified what most practicing physicians already know: prior authorization is the single largest administrative burden in outpatient medicine. Key findings:

• Physicians and staff spend an average of 13 hours per physician per week completing prior authorizations
• 94% of physicians report that PA delays lead to treatment abandonment by patients
• 89% report PA negatively impacts clinical outcomes
• Average wait time for prior authorization: 1.6 business days for urgent requests, 6.1 days for standard
• Cost to practices: approximately $82,000 per physician annually when staff time is included

Understanding which requests are most likely to be denied—and what documentation specifically unlocks approvals—allows practices to front-load the necessary documentation and avoid the resubmission cycle.

Most Denied Drug Classes and What Triggers Denial

GLP-1 Receptor Agonists (Semaglutide, Tirzepatide, Liraglutide)

GLP-1 Denial Patterns and Documentation Requirements

Most Common Denial Reason	Documentation Required for Approval
Step therapy not completed	Prior trial of metformin (+ documentation of dose, duration, response); trial of at least one other antidiabetic agent for T2DM indication; or specifically contraindicated prior agents
BMI threshold not met (for obesity indication)	BMI ≥30, or BMI ≥27 with at least one weight-related comorbidity (T2DM, HTN, dyslipidemia, OSA, NAFLD)
No documented weight loss program attempt	Structured dietary counseling (with provider name and dates), behavioral weight management program, or specific reason dietary intervention alone is insufficient
Formulary exclusion	Clinical difference documentation (patient intolerance, contraindication, or prior failure of the formulary-preferred agent); formulary exception request

2026 update: Following FDA approval of tirzepatide (Zepbound) for obesity in 2023 and expanded commercial coverage since 2024, many payers have updated their GLP-1 coverage criteria. Verify current plan-specific criteria before submitting—requirements have changed substantially from 2022–2023 policies.

Biologic and JAK Inhibitor Therapies (Rheumatology, Dermatology, GI)

Biologic medications for rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, ulcerative colitis, and moderate-to-severe plaque psoriasis face the highest prior authorization burden of any drug class—nearly universal PA requirement, with denial rates of 20–35% on first submission.

Standard step therapy requirements (vary by payer; verify each):

• Rheumatoid arthritis: methotrexate (at least 12 weeks at therapeutic dose) or equivalent DMARD failure before biologics; two DMARDs before JAK inhibitors in most plans
• Psoriatic arthritis: at least one conventional DMARD trial; specific biologic for enthesitis vs. skin disease may differ by plan
• Crohn's disease: corticosteroids and at least one immunomodulator (azathioprine, 6-MP, or methotrexate) failure before anti-TNF biologics
• Ulcerative colitis: similar to Crohn's; vedolizumab has different step requirements than anti-TNF agents
• Plaque psoriasis: phototherapy (nbUVB) documentation required by some plans before biologics, though this requirement is increasingly challenged by specialty societies

What documentation wins approval:

• Disease activity scores at time of prescribing and historically (DAS28, CDAI for RA; PASI for psoriasis; Harvey-Bradshaw or CDAI for Crohn's; Mayo Score for UC)
• Specific failed medications with dates, maximum doses reached, duration of trial, and reason for discontinuation (inadequate response vs. toxicity)
• Contraindications to step therapy agents (e.g., hepatotoxicity risk precluding methotrexate in a patient with liver disease; TB history precluding anti-TNF agents)
• Specialist (rheumatology, dermatology, gastroenterology) involvement—many payers require prescriber specialty or cosignature for biologics

ADHD Medications (Stimulants and Non-Stimulants)

Most commercial payers require step therapy through at least two stimulants before approving non-stimulant medications (atomoxetine, viloxazine, guanfacine ER, clonidine ER). For adult ADHD, some payers require a psychiatry evaluation or psychological testing documentation. Specific denial triggers:

• New diagnosis without documentation of structured assessment (ASRS, ADHD Rating Scale, Vanderbilt for pediatrics)
• Requesting a non-stimulant without prior stimulant trial
• Requesting brand when generic is available without clinical differentiation documentation

Opioid Analgesics (Chronic Pain Indication)

Extended-release and long-acting opioid formulations face significant PA burden and denial rates of 25–40% for chronic non-cancer pain. Most payers require:

• Documented failure of non-opioid pain management (NSAIDs, muscle relaxants, physical therapy, interventional procedures)
• Functional impairment documentation (pain scale AND functional status—not pain scale alone)
• Treatment agreement/informed consent for chronic opioid therapy
• PDMP check documentation
• Urine drug screen results
• Review by pain management specialist (required by some payers for doses exceeding morphine milligram equivalents thresholds)

Most Denied Procedures and What Triggers Denial

Advanced Imaging: MRI and CT

Radiology imaging PA denials typically cite "not medically necessary" or "alternative study not performed." By procedure type:

• MRI lumbar spine: Most payers require 4–6 weeks of conservative treatment (physical therapy, NSAIDs) before approving MRI for non-specific low back pain. Exception: red flag symptoms (saddle anesthesia, progressive neurological deficit, fever + back pain, history of malignancy, osteoporosis with trauma). Document red flags explicitly.
• MRI brain (headache indication): Migraine without aura does not typically require MRI per most payer guidelines. New-onset severe headache, change in headache pattern, focal neurological findings, or immunocompromised state are approvable. Document the specific clinical indication clearly.
• CT coronary angiography (CCTA): Intermediate-risk chest pain patients have strong evidence for CCTA (PROMISE trial data); payers increasingly cover this. Document pre-test probability assessment (HEART score or equivalent) to support medical necessity.

Sleep Studies

Sleep studies (both in-lab polysomnography and home sleep apnea testing) are frequently denied when documentation does not specify:

• Clinical signs and symptoms (Epworth Sleepiness Scale score, reported witnessed apneas, snoring history, nocturia, morning headache)
• BMI and neck circumference (obesity and large neck are accepted clinical risk factors)
• For CPAP resupply PA: documentation of active CPAP use (download data showing ≥4 hours/night for ≥70% of nights in a 30-day period is typically required for resupply coverage)

Physical, Occupational, and Speech Therapy

Medicare and commercial payers require functional status documentation with standardized outcome measures, treatment goals with specific timelines, and progress notes demonstrating measurable improvement. The most common denial reason: "no documented functional improvement." Therapists must document objective functional measures (FIM, PROMIS, specific gait speed, range of motion degrees) at each certification period.

Building a PA-Efficient Practice

1. Front-load documentation: Before submitting PA, ensure the chart contains the specific documentation each payer typically requires—do not wait for the denial to gather it
2. Know your top 10 PA drugs and procedures: Build a one-page quick reference for each with the specific documentation checklist
3. Use the peer-to-peer option proactively: For complex biologics, call the P2P line before submitting the written PA—understand the reviewer's criteria in advance
4. Track denial patterns by payer: Some payers have consistently more restrictive criteria for specific drug classes; knowing this allows proactive documentation adjustment

Krasyn's prior authorization module tracks active PA requests, upcoming expirations, and denial reasons by payer and drug class—giving practices the data to front-load the documentation that matters most. See how it works or review pricing.