M36.8 Systemic disorders of connective tissue in other diseases classified elsewhere

Billable ICD-10-CM code, FY2026.

Code first

• underlying disease, such as:
• alkaptonuria (E70.29)
• hypogammaglobulinemia (D80.-)
• ochronosis (E70.29)

Applies from M36 Systemic disorders of connective tissue in diseases classified elsewhere

Excludes2 (not included here)

• arthropathies in diseases classified elsewhere (M14.-)

Risk adjustment (HCC)

• CMS-HCC V22: HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
• RxHCC V08: HCC 84 — Systemic Lupus Erythematosus and Other Systemic Connective Tissue Disorders
• ESRD V24: HCC 40

MS-DRG index

Defines the logic of DRG(s) 545-547 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 710.9 Unspecified diffuse connective tissue disease (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Manifestation codes as principal diagnosis: Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and are not allowed as principal diagnosis.

Code annotations containing back-references to M36.8

Back-references to M36

• Type 2 Excludes: I77 Other disorders of arteries and arterioles ("collagen (vascular) diseases (M30-M36)")
• Type 2 Excludes: J82 Pulmonary eosinophilia, not elsewhere classified ("pulmonary eosinophilia due to systemic connective tissue disorders (M30-M36)")
• Code First: J84.170 Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere ("systemic connective tissue disorders (M30-M36)")
• Type 1 Excludes: L94 Other localized connective tissue disorders ("systemic connective tissue disorders (M30-M36)")

Diagnosis Index entries for M36.8

• Disease, diseased › connective tissue, systemic (diffuse) › in (due to) › hypogammaglobulinemia
• Disease, diseased › connective tissue, systemic (diffuse) › in (due to) › ochronosis
• Osteoarthrosis (degenerative) (hypertrophic) (joint) › deformans alkaptonurica

Nearby codes

• M36.0 Dermato(poly)myositis in neoplastic disease
• M36.1 Arthropathy in neoplastic disease
• M36.2 Hemophilic arthropathy
• M36.3 Arthropathy in other blood disorders
• M36.4 Arthropathy in hypersensitivity reactions classified elsewhere
• M36.8 Systemic disorders of connective tissue in other diseases classified elsewhere (this code)