HCPCS Code J0174: Injection, lecanemab-irmb, 1 mg

Learn about HCPCS Code J0174 for lecanemab-irmb injection with documentation and billing guidelines.

## **What is Injection of Lecanemab-irmb for Alzheimer’s Disease?** HCPCS code J0174 refers to injection lecanemab-irmb 1 mg, a monoclonal antibody therapy directed against amyloid beta plaques for the treatment of Alzheimer's disease. It is indicated for patients with mild cognitive impairment or mild dementia due to Alzheimer's and is granted traditional FDA approval. Also known as the brand name Leqembi, this therapy is typically administered in settings that meet Medicare coverage criteria, such as a CMS-approved study or clinical research study. By targeting and reducing amyloid buildup in the brain, lecanemab-irmb aims to slow disease progression and support positive clinical response. Treatment may be provided as a routine clinical service in qualifying patients or as part of an investigational clinical service in research settings. Correct use of HCPCS code J0174 ensures accurate reporting, Medicare payment, and compliance with registry and billing requirements.

## **Documentation requirements** Proper documentation for HCPCS code J0174 (injection lecanemab-irmb 1 mg) is essential to meet Medicare coverage criteria, ensure accurate Medicare payment, and maintain compliance for patients receiving treatment for Alzheimer’s disease. Records must confirm that the prescribing clinician is following traditional FDA approval guidelines and that the patient meets the required clinical criteria. ### **Patient eligibility and diagnosis** Documentation should specify that the patient has mild cognitive impairment or mild dementia due to Alzheimer’s, with diagnosis following dx codes. The record should also note the presence of amyloid beta plaques as detected through imaging, fulfilling the criteria for treatment with monoclonal antibodies directed against amyloid. ### **Study and service classification** Indicate whether the therapy is being given as a routine clinical service provided under a CMS-approved study or approved clinical research study, or as an investigational clinical service within a qualifying study. Include the registry trial number or dedicated NCT number when applicable. ### **Clinical and procedural details** Providers must document: - The dose of lecanemab-irmb 1 mg administered, and the infusion details. MRI before treatment initiation to establish baseline and assess for ARIA-H or other safety concerns. - Any follow-up MRI for radiographic stabilization. - The patient’s symptoms before and after therapy, noting any positive clinical response. ### **Administrative and billing information** Include the claim form, revenue code, narrative description field, and any required billing instructions. State whether the code Leqembi uses was approved on a case-by-case basis or under initial approval. Ensure that all required details are submitted and that documentation is complete to answer potential treatment questions from payers.

## **Billing requirements** According to WPS Government Health Administrators (2025), for billing HCPCS code J0174 (injection lecanemab‑irmb 1 mg), providers should: - Use correct code and billing units: Report each 1 mg administered under HCPCS code J0174, aligned with the billing unit structure. - Ensure coverage under Medicare: Lecanemab (Leqembi) is only reimbursable when administered as part of a CMS‑approved study or approved clinical research study, per Medicare coverage criteria under NCD 200.3 - Document clinical justification: Confirm that the patient has Alzheimer’s disease with mild cognitive impairment or mild dementia, and that the treatment targets amyloid beta plaques with a monoclonal antibody. - Include registry identifiers: If part of a study, include the registry trial number or dedicated NCT number on the claim form. - Support with diagnostic imaging: Submit evidence of a prior MRI establishing baseline status, and any follow-up MRI documentation if used to monitor radiographic stabilization or ARIA-H. - Answer treatment questions: Provide a narrative description and billing instructions to address how therapy met initial approval criteria or was used on a case-by-case basis. - Align with payer requirements: Follow all payer-specific billing instructions, including use of proper revenue codes, claim form details, and adherence to submission standards to facilitate Medicare payment.

## **Other relevant codes** - J0175 – Injection, donanemab-azbt, 2 mg - Donanemab-azbt, marketed under the brand name Kisunla, is a monoclonal antibody used to treat Alzheimer's disease.

Frequently asked questions

Leqembi is administered as an intravenous infusion in a clinical setting, often every two weeks. Each billing unit under HCPCS code J0174 represents 1 mg of the drug, so providers must report the exact dosage given during the session.

Baseline MRI scans help detect any pre-existing brain changes or risks, such as amyloid-related imaging abnormalities with hemosiderin deposition (ARIA-H). This ensures patient safety before the first infusion and guides monitoring during treatment.

Yes, but only if they meet Medicare’s National Coverage Determination (NCD 200.3) criteria, which currently limits coverage to certain CMS-approved studies or qualifying clinical research. Providers must document how the patient meets these requirements and include the study or registry number on the claim.