Rituximab (J9312, Q5115, Q5119): Medicare covered diagnoses & ICD-10 codes

What Medicare pays for Rituximab (2026 Q2)

Once a claim carries a covered diagnosis, Medicare Part B reimburses the drug at the ASP + 6% payment limit. Current allowed amounts per billing unit:

Source: CMS ASP Drug Pricing File, 2026 Q2. Payment = ASP + 6% per unit; multiply by units billed (watch JZ/JW wastage). Your patient's share is typically 20% after the deductible. Estimate the full cost & patient out-of-pocket →

Rituximab is a physician-administered biologic billed under Medicare Part B (not the Part D pharmacy benefit). Under Part B, Medicare pays the practice for the drug (HCPCS J9312, Q5115, Q5119, Q5123, J9311, J3590) plus its administration — but only when the claim's diagnosis (ICD-10) code supports medical necessity. Each MAC publishes the specific covered diagnoses in a Billing & Coding Article; a claim with a diagnosis outside that list is typically denied as not medically necessary (CO-50).

Covered ICD-10 diagnoses for Rituximab

The 692 codes below are the diagnoses Palmetto GBA accepts for J9312 under Article A56380, grouped exactly as CMS groups them and organized by condition category for scanning. Use the filter in each group to find a specific code or condition.

How to use this list when billing

Put the patient's covered ICD-10 diagnosis on the claim line with J9312 and confirm your documentation supports medical necessity. Match the right product code (reference vs biosimilar) and units, and check the diagnosis against the article for your MAC, since the list above is Palmetto GBA policy.

LCD vs. Billing & Coding Article vs. NCD

An LCD (Local Coverage Determination) is a MAC's policy on whether a service is reasonable and necessary in its region, and its companion Billing & Coding Article holds the covered ICD-10 and HCPCS code lists. A NCD (National Coverage Determination), where one exists, applies nationwide. For Rituximab, the code lists live in Article A56380 (tied to LCD L35026) — CMS moved code lists out of LCDs and into Articles, which is why the diagnoses live in the Article, not the LCD.

Common Rituximab denial reasons