M08.4A: Pauciarticular juvenile rheumatoid arthritis, other specified site

M08.4A, pauciarticular juvenile rheumatoid arthritis, other specified site, is listed as a covered diagnosis in 6 Medicare billing and coding articles that apply to 18 HCPCS Level II codes, including J9312 (Injection, rituximab, 10 mg), Q5123 (Injection, rituximab-arrx, biosimilar, (riabni), 10 mg), Q5119 (Injection, rituximab-pvvr, biosimilar, (ruxience), 10 mg). The articles come from 3 Medicare contractors. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.

HCPCS Level II codes with M08.4A as a covered diagnosis

CodeDescriptionMedicare coverageDMEPOS fee 2026 (state range)Articles listing it
J9312Injection, rituximab, 10 mgSpecial coverage instructions apply—2
Q5123Injection, rituximab-arrx, biosimilar, (riabni), 10 mgCarrier judgment—2
Q5119Injection, rituximab-pvvr, biosimilar, (ruxience), 10 mgCarrier judgment—2
Q5115Injection, rituximab-abbs, biosimilar, (truxima), 10 mgSpecial coverage instructions apply—2
J9260Injection, methotrexate sodium, 50 mgSpecial coverage instructions apply—1
J9215Injection, interferon, alfa-n3, (human leukocyte derived), 250,000 iuSpecial coverage instructions apply—1
J9311Injection, rituximab 10 mg and hyaluronidaseSpecial coverage instructions apply—1
J3590Unclassified biologicsCarrier judgment—1
G0283Electrical stimulation (unattended), to one or more areas for indication(s) other than wound care, as part of a therapy plan of careCarrier judgment—2
A9585Injection, gadobutrol, 0.1 mlCarrier judgment—1
Q9953Injection, iron-based magnetic resonance contrast agent, per mlSpecial coverage instructions apply—1
G0152Services performed by a qualified occupational therapist in the home health or hospice setting, each 15 minutesCarrier judgment—1
G0158Services performed by a qualified occupational therapist assistant in the home health or hospice setting, each 15 minutesCarrier judgment—1
G0160Services performed by a qualified occupational therapist, in the home health setting, in the establishment or delivery of a safe and effective occupational therapy maintenance program, each 15 minutesCarrier judgment—1
G2169Services performed by an occupational therapist assistant in the home health setting in the delivery of a safe and effective occupational therapy maintenance program, each 15 minutesCarrier judgment—1
G0281Electrical stimulation, (unattended), to one or more areas, for chronic stage iii and stage iv pressure ulcers, arterial ulcers, diabetic ulcers, and venous stasis ulcers not demonstrating measurable signs of healing after 30 days of conventional care, as part of a therapy plan of careCarrier judgment—1
G0329Electromagnetic therapy, to one or more areas for chronic stage iii and stage iv pressure ulcers, arterial ulcers, diabetic ulcers and venous stasis ulcers not demonstrating measurable signs of healing after 30 days of conventional care as part of a therapy plan of careCarrier judgment—1
G0255Current perception threshold/sensory nerve conduction test, (snct) per limb, any nerveNon-covered by MedicareNot covered1

Medicare policy articles listing M08.4A

A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.

Other M08 diagnoses (Juvenile arthritis)

Frequently asked questions

Does Medicare cover M08.4A (Pauciarticular juvenile rheumatoid arthritis, other…)?

Medicare covers items and services, not diagnoses. 6 Medicare billing and coding articles list M08.4A as a covered diagnosis for 18 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.

Which HCPCS codes can be billed with ICD-10 M08.4A?

The Level II codes from the policies most specific to this diagnosis are J9312 (Injection, rituximab, 10 mg, 2 articles); Q5123 (Injection, rituximab-arrx, biosimilar, (riabni), 10 mg, 2 articles); Q5119 (Injection, rituximab-pvvr, biosimilar, (ruxience), 10 mg, 2 articles); Q5115 (Injection, rituximab-abbs, biosimilar, (truxima), 10 mg, 2 articles); J9260 (Injection, methotrexate sodium, 50 mg, 1 article). Code choice depends on the item supplied; check each code's descriptor.

Which Medicare policy articles list M08.4A?

A55639 (Billing and Coding: Chemotherapy Agents for Non-Oncologic Conditions); A56380 (Billing and Coding: Rituximab); A57478 (Billing and Coding: Nerve Conduction Studies and Electromyography), and 3 more articles.

What is ICD-10-CM code M08.4A?

M08.4A is the ICD-10-CM code for pauciarticular juvenile rheumatoid arthritis, other specified site, in category M08 (Juvenile arthritis), chapter 13: Diseases of the musculoskeletal system and connective tissue.

Next steps

Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.

Chapter 13: Diseases of the musculoskeletal system and connective tissue · All diagnoses · HCPCS lookup