M46.1 Sacroiliitis, not elsewhere classified

Billable ICD-10-CM code, FY2026.

Risk adjustment (HCC)

• CMS-HCC V22: HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
• ESRD V24: HCC 40

MS-DRG index

Defines the logic of DRG(s) 551-552 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 720.2 Sacroiliitis, not elsewhere classified

Code annotations containing back-references to M46.1

Back-references to M46

• Type 1 Excludes: G55 Nerve root and plexus compressions in diseases classified elsewhere ("nerve root compression (due to) (in) spondylopathies (M46.-, M48.-)")

Diagnosis Index entries for M46.1

• Change (s) (in) (of) › inflammatory › sacroiliac
• Inflammation, inflamed, inflammatory (with exudation) › joint NEC › sacroiliac
• Sacroiliitis NEC
• Spondylitis (chronic) › sacroiliac NEC

Nearby codes

• M46.05 Spinal enthesopathy, thoracolumbar region
• M46.06 Spinal enthesopathy, lumbar region
• M46.07 Spinal enthesopathy, lumbosacral region
• M46.08 Spinal enthesopathy, sacral and sacrococcygeal region
• M46.09 Spinal enthesopathy, multiple sites in spine
• M46.1 Sacroiliitis, not elsewhere classified (this code)
• M46.2 Osteomyelitis of vertebra
• M46.20 Osteomyelitis of vertebra, site unspecified
• M46.21 Osteomyelitis of vertebra, occipito-atlanto-axial region
• M46.22 Osteomyelitis of vertebra, cervical region
• M46.23 Osteomyelitis of vertebra, cervicothoracic region