Pyogenic (bacterial) infection of the intervertebral disc at the lumbosacral junction (L5–S1 level), classified under other inflammatory spondylopathies.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 7
- Region
- Spine
Documentation tips
What should appear in the chart to support M46.37.
Source · Editorial brief grounded in 5 cited references ↓
- Specify 'lumbosacral region' or 'L5–S1 disc space' explicitly in the note — vague terms like 'lumbar discitis' without level may be mapped to a less specific code.
- Always document the suspected or confirmed causative organism so the required B95–B97 secondary code can be assigned accurately.
- Record MRI findings that support pyogenic etiology: T2 hyperintensity, endplate edema/erosion, contrast enhancement, or paravertebral/epidural abscess.
- Note relevant labs (ESR, CRP, blood cultures, disc aspiration/biopsy results) in the assessment to support the 'pyogenic' qualifier over unspecified discitis.
- If vertebral osteomyelitis is also present, document it separately so both M46.37 and M46.27 can be coded when clinically supported.
- Document conservative treatment history or failed antibiotic courses when coding encounters related to escalation of care or surgical intervention.
Related CPT procedures
Procedure codes commonly billed with M46.37. 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 M46.37 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Omitting the mandatory B95–B97 organism code: M46.3x codes carry a 'use additional code' instruction — submitting M46.37 alone is incomplete per ICD-10-CM tabular guidelines.
- Using M46.37 for unspecified or suspected (non-confirmed) discitis: if pyogenic etiology is not documented, use M46.46 (discitis, unspecified, lumbosacral region) instead.
- Confusing lumbosacral (M46.37, L5–S1 region) with lumbar (M46.36, L1–L5 region) — the 6th character drives regional specificity; verify the affected level in the operative or imaging report.
- Coding M46.37 alone when vertebral osteomyelitis is concurrently documented — M46.27 should be added as a secondary diagnosis when the vertebral body is also infected.
- Mapping 'spondylodiscitis' directly to M46.37 without confirming pyogenic etiology — tuberculous spondylodiscitis codes to M49.07, not M46.3x.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M46.37 codes a pyogenic discitis specifically localized to the lumbosacral region — the disc space at or adjacent to the L5–S1 junction. Use this code when imaging (MRI with contrast is standard), laboratory markers (elevated ESR, CRP, white count), or biopsy/culture confirm bacterial infection of the disc itself at that spinal level. The 'pyogenic' qualifier means a pus-forming bacterial process, not fungal, tuberculous, or other granulomatous infection; those require different codes.
The ICD-10-CM tabular instruction at the parent code M46.3 requires an additional code from B95–B97 to identify the causative organism (e.g., B95.62 for MRSA, B96.20 for unspecified E. coli). Failing to append that secondary code leaves the claim incomplete per coding guidelines and may trigger a payer query. If the organism has not yet been identified at the time of coding, document that cultures are pending — you can update the organism code once results return.
Distinguish M46.37 from M46.46 (discitis, unspecified, lumbosacral region), which is appropriate when infection is suspected but pyogenic etiology is not confirmed, and from M46.27 (osteomyelitis of vertebra, lumbosacral), which applies when the vertebral body itself is the primary infected structure rather than the disc space. The two conditions frequently coexist; code both when documentation supports both diagnoses.
Sibling codes
Other billable codes under M46.3 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01Is M46.37 billable on its own, or does it always require a secondary code?
02What is the difference between M46.37 and M46.46 for lumbosacral discitis?
03Does M46.37 cover the L5–S1 disc or the lumbar discs above it?
04Can M46.37 and M46.27 be coded together on the same claim?
05Which CPT procedures are commonly paired with M46.37?
06Does a positive blood culture alone justify coding M46.37 with the organism code?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (FY2026, effective Oct 1, 2025)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M45-M49/M46-/M46.37
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M46.37
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M46.3
- 05icdcodes.aihttps://icdcodes.ai/icd10/M46.37
Mira AI Scribe
Mira AI Scribe captures spinal level (L5–S1 or lumbosacral), confirmation of pyogenic versus unspecified etiology, MRI/imaging findings (endplate changes, disc signal, abscess), lab markers (ESR, CRP, cultures), and identified organism — preventing downcoding to unspecified discitis M46.46, a missing secondary organism code audit flag, and incorrect level assignment between M46.36 and M46.37.
See how Mira captures M46.37 documentation