Inflammatory disease of the sacral or sacrococcygeal spine that is specified by the clinician but does not map to a more precise inflammatory spondylopathy code in the M46 category.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 12
- Region
- Spine
Documentation tips
What should appear in the chart to support M46.88.
Source · Editorial brief grounded in 5 cited references ↓
- Document the specific inflammatory condition by name (e.g., psoriatic spondylitis, reactive spondylitis) to justify 'other specified' over unspecified codes.
- Confirm in the note that the sacral or sacrococcygeal region is the documented site of inflammation — not lumbar (M46.86) or lumbosacral (M46.87).
- Include imaging findings that support an inflammatory process: bone marrow edema on MRI, erosive changes, or sacral sclerosis on plain films.
- If a systemic inflammatory condition (e.g., psoriatic arthritis, IBD-related arthropathy) is driving the spondylopathy, code the underlying disease first and use M46.88 as an additional code per any applicable 'code first' or 'code also' instruction.
- Record whether conservative treatment (NSAIDs, PT, biologics) has been attempted — relevant for prior auth on advanced imaging and procedural coverage.
Related CPT procedures
Procedure codes commonly billed with M46.88. Linking the right diagnosis to the right procedure is what establishes medical necessity.
Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis
Common coding pitfalls
The recurring mistakes coders make with M46.88 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Using M46.88 when M46.1 (sacroiliac joint inflammation) is the more specific match — M46.1 has its own code and should be used when SI joint inflammation is explicitly documented.
- Defaulting to M46.88 for ankylosing spondylitis involving the sacrum — ankylosing spondylitis maps to M45.x, not M46.8x.
- Selecting M46.87 (lumbosacral region) when the provider documents sacral or coccygeal involvement only — region specificity determines the 8th character.
- Coding M46.88 without a secondary code for the underlying systemic disease when one is present and a 'code also' annotation applies.
- Confusing M46.88 with M53.88 (other specified dorsopathies, sacral and sacrococcygeal region) — M53.88 covers non-inflammatory sacrococcygeal disorders; M46.88 requires documented inflammatory etiology.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M46.88 applies when the treating provider documents a named, specified inflammatory spondylopathy — one that is not ankylosing spondylitis (M45), sacroiliac inflammation (M46.1), or discitis (M46.4x) — and the affected region is the sacral or sacrococcygeal spine. Typical scenarios include inflammatory arthropathies such as psoriatic spondylitis, reactive spondylitis, or enteropathic spondylitis when the inflammatory process is localized to the sacrum or coccyx and no more precise code exists for that combination of condition and region.
Within the M46.8x family, the 8th character designates spinal region: M46.80 = site unspecified, M46.81 = occipito-atlanto-axial, M46.82 = cervical, M46.83 = cervicothoracic, M46.84 = thoracic, M46.85 = thoracolumbar, M46.86 = lumbar, M46.87 = lumbosacral, M46.88 = sacral/sacrococcygeal, M46.89 = multiple sites. Use M46.88 only when pathology is documented at the sacral or sacrococcygeal level specifically, not when the lumbar spine is the primary site.
This code groups to MS-DRG 551 (Medical back problems with MCC) or 552 (Medical back problems without MCC). When coding sacroiliac joint conditions, verify whether the clinical picture better fits M46.1 (sacroiliac joint inflammation) or M53.3 (sacrococcygeal disorders) before landing on M46.88 — the distinction turns on whether the provider characterizes the process as inflammatory spondylopathy versus a non-inflammatory sacrococcygeal disorder.
Sibling codes
Other billable codes under M46.8 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01When should I use M46.88 instead of M46.1 for sacroiliac conditions?
02Can M46.88 be used as a primary diagnosis for an SI joint injection encounter?
03Does M46.88 require a 7th character?
04How does M46.88 differ from M53.88?
05Should I code the underlying systemic disease alongside M46.88?
06What MS-DRG does M46.88 map to?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M46-/M46.88
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M46.88
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M46.8
- 05aapc.comhttps://www.aapc.com/codes/icd-10-codes/M46
Mira AI Scribe
Mira captures the provider's named inflammatory diagnosis, the documented spinal region (sacral or sacrococcygeal), imaging findings (MRI marrow edema, erosions, sacral sclerosis), and any linked systemic condition. This prevents a drop to M46.80 (site unspecified) or misassignment to M46.1 or M53.88, and ensures the encounter supports MS-DRG 551/552 grouping without an audit flag for vague anatomic localization.
See how Mira captures M46.88 documentation