What is ICD-10 code M08.452?

M08.452 is the ICD-10-CM diagnosis code for Pauciarticular juvenile rheumatoid arthritis, left hip. A type of childhood arthritis affecting only a few joints, specifically involving the left hip. This causes inflammation and potential joint damage in the hip area. M08.452 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M08.452 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. M08.452 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. M08.452 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 M08.452 map to under V28?

M08.452 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 M08.452: Pauciarticular juvenile

M08.452 maps to CMS-HCC V28 93. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

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Code lookupM08.452Effective 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)

M08.452

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

Pauciarticular juvenile rheumatoid arthritis, left hip

A type of childhood arthritis affecting only a few joints, specifically involving the left hip. This causes inflammation and potential joint damage in the hip area.

Buddy Insight

Pauciarticular juvenile rheumatoid arthritis affecting the left hip represents a chronic inflammatory condition requiring comprehensive pediatric rheumatologic care.

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

M08.4Pauciarticular juvenile rheumatoid arthritis

M08.45Pauciarticular juvenile rheumatoid arthritis, hip

M08.452Pauciarticular juvenile rheumatoid arthritis, left hip

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for M08.452 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for M08.452 in this effective period.

Related Child Codes

Official

M08.451Pauciarticular juvenile rheumatoid arthritis, right hip

M08.459Pauciarticular juvenile rheumatoid arthritis, unspecified hip

Includes

Official

ICD-10-CM does not list Includes notes for M08.452 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for M08.452 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for M08.452 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for M08.452 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for M08.452 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Physician documentation of juvenile rheumatoid arthritis with pauciarticular pattern

Clear specification of left hip joint involvement

Clinical evidence of joint inflammation (pain, swelling, limited range of motion)

Pediatric onset documentation (before age 16)

MEAT Support

HCC Buddy guidance

Physician documentation of juvenile rheumatoid arthritis with pauciarticular pattern

Clear specification of left hip joint involvement

Clinical evidence of joint inflammation (pain, swelling, limited range of motion)

Pediatric onset documentation (before age 16)

Audit Caution

HCC Buddy guidance

Incorrect laterality coding when documentation specifies left versus right hip

Using unspecified codes when specific joint involvement is clearly documented

Confusing different juvenile arthritis subtypes (pauciarticular vs polyarticular)

Coding symptom codes instead of definitive diagnosis codes

Common Mistakes

HCC Buddy guidance

M08.451 — Right hip involvement versus left hip

M08.459 — Unspecified hip versus documented left hip involvement

M08.40 — Pauciarticular JRA unspecified site versus specific hip documentation

M25.552 — Pain in left hip versus established inflammatory arthritis

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 M08.452 an HCC code?

Yes. M08.452 (Pauciarticular juvenile rheumatoid arthritis, left 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: M08.452 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: M08.452
Description: Pauciarticular juvenile rheumatoid arthritis, left 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 M08.452 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for M08.452

For M08.452 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

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

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed M08.452 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

M08.452 is the ICD-10-CM diagnosis code for pauciarticular juvenile rheumatoid arthritis, left hip. A type of childhood arthritis affecting only a few joints, specifically involving the left hip. This causes inflammation and potential joint damage in the hip area. M08.452 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, M08.452 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 M08.452; use the applicable model and payment year when reviewing the V28 mapping. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. 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 left hip is the affected side in the medical documentation. Because M08.452 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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 M08.452 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify left hip is the affected side in the medical documentation
•Hip involvement may require physical therapy and functional assessment documentation

Clinical Significance

Pauciarticular juvenile rheumatoid arthritis affecting the left hip represents a chronic inflammatory condition requiring comprehensive pediatric rheumatologic care. Early diagnosis and treatment are crucial to prevent joint destruction, growth abnormalities, and functional impairment that can significantly impact the child's development and long-term mobility.

Documentation Requirements

✓Physician documentation of juvenile rheumatoid arthritis with pauciarticular pattern
✓Clear specification of left hip joint involvement
✓Clinical evidence of joint inflammation (pain, swelling, limited range of motion)
✓Pediatric onset documentation (before age 16)
✓Inflammatory markers and rheumatologic laboratory studies
✓Imaging studies showing joint involvement when performed
✓Assessment of functional limitations and impact on daily activities
✓Multidisciplinary care plan including rheumatology management