M46.1
BillableSacroiliitis, not elsewhere classified
HCC Category Mapping
V24HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.307ESRDHCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.000What This Code Means
Inflammation of the sacroiliac joint (where the spine connects to the pelvis) that is not caused by infection or other specified conditions.
Coding Tips
- •Sacroiliitis can be associated with ankylosing spondylitis or other spondyloarthropathies; check for additional diagnosis codes
- •Differentiate from infectious sacroiliitis (M46.2x) by confirming absence of osteomyelitis or other infection
Clinical Significance
Sacroiliitis represents significant inflammatory disease of the sacroiliac joint, causing chronic pain and functional limitation. This condition often indicates underlying inflammatory arthropathy and requires long-term management with anti-inflammatory treatments.
Documentation Requirements
- ✓Documentation of inflammation specifically in sacroiliac joint
- ✓Clinical symptoms of sacroiliitis including pain and stiffness
- ✓Physical examination findings consistent with sacroiliac joint inflammation
- ✓Imaging studies confirming sacroiliitis (MRI, CT, or X-ray)
- ✓Exclusion of infectious causes of sacroiliitis
- ✓Documentation that condition is not elsewhere classified
- ✓Assessment of inflammatory markers if obtained
- ✓Functional impact assessment on mobility and daily activities
Commonly Confused Codes
M45 — Ankylosing spondylitis includes sacroiliitis but has specific diagnostic criteriaA18.01 — Tuberculous sacroiliitis is infectious, not inflammatoryM46.30 — Infection of intervertebral disc affects different structuresM53.3 — General sacrococcygeal disorders are less specificM25.571/M25.572 — Sacroiliac joint pain without documented inflammation
Code Hierarchy
└M46Other inflammatory spondylopathies└M46.1Sacroiliitis, not elsewhere classified
└M46.1Sacroiliitis, not elsewhere classified