Medical Coding & Billing Guidelines for GLP-1 Medications
What Coders Need to Know About Coverage, Documentation, and Compliance
Glucagon-Like Peptide-1 (GLP-1) receptor agonists have become some of the most commonly prescribed medications in the U.S., driven by their effectiveness in treating type 2 diabetes and, more recently, obesity. As utilization increases, so does payer scrutiny. For medical coders and billers, accurate coding, documentation, and payer compliance are essential to avoid denials, audits, and recoupments.
This guide breaks down the coding and billing rules for GLP-1 medications and provides practical tips for clean claims and compliant reimbursement.
What Are GLP-1 Medications?
GLP-1 receptor agonists mimic the incretin hormone GLP-1, which stimulates insulin secretion, suppresses glucagon, slows gastric emptying, and promotes satiety.
Common GLP-1 medications include:
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Semaglutide (Ozempic®, Wegovy®)
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Liraglutide (Victoza®, Saxenda®)
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Dulaglutide (Trulicity®)
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Tirzepatide (Mounjaro®, Zepbound®)
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Exenatide (Byetta®, Bydureon®)
These drugs are prescribed for:
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Type 2 diabetes mellitus
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Chronic weight management (when FDA-approved for obesity)
Diagnosis Coding: Medical Necessity Is Everything
Diagnosis coding drives coverage for GLP-1 medications. Payers closely monitor off-label use.
Common ICD-10-CM Codes
Type 2 Diabetes
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E11.9 – Type 2 diabetes mellitus without complications
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E11.65 – Type 2 diabetes mellitus with hyperglycemia
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E11.8 – Type 2 diabetes mellitus with unspecified complications
Obesity / Weight Management
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E66.9 – Obesity, unspecified
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E66.01 – Morbid (severe) obesity due to excess calories
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Z68.30–Z68.45 – BMI codes (required by many payers)
Prediabetes (often not covered for GLP-1)
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R73.03 – Prediabetes
Key Coding Tip
Most payers cover GLP-1 medications only for FDA-approved indications. Weight-loss drugs are often excluded from pharmacy benefits unless the employer plan opts in.
HCPCS Coding for GLP-1 Medications
When GLP-1 drugs are administered in a clinical setting (not retail pharmacy), coders may bill using HCPCS J-codes.
Common examples:
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J3490 – Unclassified drugs (used when no permanent code exists)
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J3590 – Unclassified biologics
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J1817 – Insulin (some combo therapies)
Many GLP-1 drugs are processed under a pharmacy benefit rather than a medical benefit. In those cases, claims are billed through the patient’s pharmacy plan and not on a CMS-1500 or UB-04.
Key Coding Tip
Always verify whether the drug is billed under:
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Medical benefit (buy-and-bill model)
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Pharmacy benefit (retail or specialty pharmacy)
CPT Coding for GLP-1 Related Visits
GLP-1 prescriptions are commonly tied to E/M visits, obesity counseling, or diabetes management.
Common CPT Codes
Office Visits (2021 E/M Guidelines)
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99202–99205 – New patient visits
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99211–99215 – Established patient visits
Obesity Counseling
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99401–99404 – Preventive counseling (commercial payers)
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G0447 – Face-to-face obesity counseling (Medicare)
Diabetes Self-Management Training
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G0108 – Individual DSMT
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G0109 – Group DSMT
Prior Authorization & Payer Policy Requirements
Most payers require prior authorization (PA) for GLP-1 medications.
Typical PA requirements include:
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Confirmed diagnosis of type 2 diabetes or obesity
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Documented BMI (often ≥30 or ≥27 with comorbidities)
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Failed trials of other medications
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Lifestyle modification attempts
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Recent A1C lab values (for diabetes)
Documentation Must Include
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Height and weight with calculated BMI
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Diagnosis supporting medical necessity
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Treatment plan
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Follow-up and monitoring plan
Compliance & Audit Risk
GLP-1 medications are a high-risk audit target due to:
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Rapid growth in utilization
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High drug cost
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Off-label prescribing
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Weight-loss demand
Common audit issues:
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Incorrect diagnosis codes
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Missing BMI documentation
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Lack of medical necessity
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Billing weight-loss drugs to Medicare
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Inappropriate use of unclassified J-codes
Medicare Coverage Rules
Medicare Part D generally does not cover weight-loss drugs, even if FDA-approved for obesity.
However, Medicare does cover GLP-1 medications for diabetes.
Important Rule
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Wegovy® and Zepbound® are not covered by Medicare for obesity.
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Ozempic® and Mounjaro® may be covered when prescribed for diabetes.
Coding Best Practices for GLP-1 Claims
Always verify payer coverage policies
Confirm FDA-approved indication
Use the most specific ICD-10 code
Include BMI codes when required
Ensure documentation supports medical necessity
Confirm whether the drug is pharmacy or medical benefit
Avoid unclassified J-codes unless required
Track prior authorization approvals
Document patient counseling and monitoring
Watch for Medicare weight-loss exclusions
Denial Prevention Checklist
Before submitting GLP-1-related claims, confirm:
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Correct diagnosis code selection
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BMI documented and coded
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PA approval on file
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Proper benefit type (pharmacy vs medical)
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E/M level supported by documentation
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Drug coverage confirmed by payer
GLP-1 medications are transforming diabetes and obesity care, but they bring complex billing and compliance challenges. For medical coders, success depends on accurate diagnosis selection, payer policy knowledge, prior authorization tracking, and airtight documentation.
As payer oversight continues to increase, GLP-1 coding will remain a high-impact, high-risk area that requires careful attention to detail and constant policy updates.