What is ICD-10 code M08.251?

M08.251 is the ICD-10-CM diagnosis code for Juvenile rheumatoid arthritis with systemic onset, right hip. A type of childhood arthritis that affects the right hip and causes inflammation throughout the body, including fever and rash. M08.251 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M08.251 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. M08.251 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. M08.251 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does M08.251 map to under V28?

M08.251 maps to CMS-HCC V28 HCC 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM M08.251: Juvenile rheumatoid

M08.251 maps to CMS-HCC V28 93. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

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Code lookupM08.251

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Inflammatory polyarthropathies (M05-M14)

M08.251

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Juvenile rheumatoid arthritis with systemic onset, right hip

A type of childhood arthritis that affects the right hip and causes inflammation throughout the body, including fever and rash.

Buddy Insight

Juvenile rheumatoid arthritis with systemic onset represents a severe form of childhood arthritis with significant systemic inflammation requiring intensive management.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 93

Rheumatoid Arthritis and Othe...

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 056

HHS-HCC 056 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 40

Rheumatoid Arthritis and Infl...

Code-level coefficient reference

RXHCC

Mapped

HCC 83

Rheumatoid Arthritis and Othe...

Code-level coefficient reference

Code Book Path

Official

M08.2Juvenile rheumatoid arthritis with systemic onset M08.25Juvenile rheumatoid arthritis with systemic onset, hip M08.251Juvenile rheumatoid arthritis with systemic onset, right hip

Inclusion Terms

Official

Still's disease NOSInherited from M08.2

Excludes 2

Official

arthropathic psoriasis (L40.5-)Inherited from M00-M99
certain conditions originating in the perinatal period (P04-P96)Inherited from M00-M99
certain infectious and parasitic diseases (A00-B99)Inherited from M00-M99
compartment syndrome (traumatic) (T79.A-)Inherited from M00-M99
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from M00-M99
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from M00-M99
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from M00-M99
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from M00-M99
neoplasms (C00-D49)Inherited from M00-M99
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from M00-M99

Related Codes

Official

M08.252Juvenile rheumatoid arthritis with systemic onset, left hip M08.259Juvenile rheumatoid arthritis with systemic onset, unspecified hip

Includes

Official

No Includes notes are included in this display for M08.251. Check the code and parent instructions in the Code Book.

Excludes 1

Official

arthropathy in Whipple's disease (M14.8)Inherited from M08, M08.2
Felty's syndrome (M05.0)Inherited from M08, M08.2
juvenile dermatomyositis (M33.0-)Inherited from M08, M08.2
psoriatic juvenile arthropathy (L40.54)Inherited from M08, M08.2
adult-onset Still's disease (M06.1-)Inherited from M08, M08.2

Code First

Official

No Code First sequencing instructions are included in this display for M08.251. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for M08.251. Check the code and parent instructions in the Code Book.

Code Also

Official

any associated underlying condition, such as:Inherited from M08
regional enteritis [Crohn's disease] (K50.-)Inherited from M08
ulcerative colitis (K51.-)Inherited from M08

Buddy Documentation Tip

HCC Buddy guidance

Patient age at onset (must be under 16 years)

Evidence of systemic symptoms (fever, rash, lymphadenopathy, hepatosplenomegaly)

Documentation of right hip joint involvement with inflammation

Laboratory evidence of systemic inflammation (elevated ESR, CRP)

MEAT Support

HCC Buddy guidance

Patient age at onset (must be under 16 years)

Evidence of systemic symptoms (fever, rash, lymphadenopathy, hepatosplenomegaly)

Documentation of right hip joint involvement with inflammation

Laboratory evidence of systemic inflammation (elevated ESR, CRP)

Audit Caution

HCC Buddy guidance

Coding adult rheumatoid arthritis codes when patient had juvenile onset

Using unspecified site codes when specific hip involvement is documented

Failing to distinguish between systemic onset JRA and other JRA subtypes

Missing the requirement for laterality specification in hip involvement

Common Mistakes

HCC Buddy guidance

M08.20 — Juvenile rheumatoid arthritis with systemic onset, unspecified site (use when specific joint not documented)

M08.3 — Juvenile rheumatoid polyarthritis seronegative (affects multiple joints without systemic symptoms)

M25.551 — Pain in right hip (symptom code, not diagnostic)

M24.751 — Osteophyte, right hip (degenerative changes, not inflammatory)

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is M08.251 an HCC code?

Yes. M08.251 (Juvenile rheumatoid arthritis with systemic onset, right hip) maps to HCC 93, Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.617. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: M08.251 is billable and maps to V28 HCC 93, Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: M08.251
Description: Juvenile rheumatoid arthritis with systemic onset, right hip
HCC (V28): HCC 93 — Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders
RAF reference coefficient: 0.617
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 93, Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders

0.617

ESRDHCC 40, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

Not separately weighted

RxHCCHCC 83, Rheumatoid Arthritis and Other Inflammatory Polyarthropathy

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work M08.251 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for M08.251

For M08.251, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

M08.251 is the ICD-10-CM diagnosis code for juvenile rheumatoid arthritis with systemic onset, right hip. A type of childhood arthritis that affects the right hip and causes inflammation throughout the body, including fever and rash. M08.251 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering inflammatory polyarthropathies (m05-m14).

Under the CMS-HCC V28 risk adjustment model, M08.251 maps to Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders (HCC 93) with a source-labeled community, non-dual, aged reference coefficient of 0.617. No V24 mapping is shown for M08.251; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Verify right hip is specifically documented; hip involvement in systemic JRA is clinically significant. For M08.251, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for M08.251 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify right hip is specifically documented; hip involvement in systemic JRA is clinically significant
•Note any functional limitations or mobility restrictions related to hip involvement

Clinical Significance

Juvenile rheumatoid arthritis with systemic onset represents a severe form of childhood arthritis with significant systemic inflammation requiring intensive management. Hip involvement in JRA is particularly concerning due to potential for growth disturbances and significant functional impairment requiring aggressive treatment.

Documentation Requirements

✓Patient age at onset (must be under 16 years)
✓Evidence of systemic symptoms (fever, rash, lymphadenopathy, hepatosplenomegaly)
✓Documentation of right hip joint involvement with inflammation
✓Laboratory evidence of systemic inflammation (elevated ESR, CRP)
✓Exclusion of other causes of arthritis and systemic illness
✓Duration of symptoms (minimum 6 weeks for JRA diagnosis)
✓Physical examination findings of hip joint limitation, pain, or swelling
✓Assessment of functional impact including gait abnormalities

Commonly Confused Codes

•M08.20: Juvenile rheumatoid arthritis with systemic onset, unspecified site (use when specific joint not documented)
•M08.3: Juvenile rheumatoid polyarthritis seronegative (affects multiple joints without systemic symptoms)
•M25.551: Pain in right hip (symptom code, not diagnostic)
•M24.751: Osteophyte, right hip (degenerative changes, not inflammatory)
•K59.4: Anal spasm (anatomical confusion with hip region)