Spondylolisthesis localized to the thoracolumbar junction — the transitional segment where the thoracic spine meets the lumbar spine, typically at the T12-L1 level.
Verified May 8, 2026 · 4 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 20
- Region
- Spine
Documentation tips
What should appear in the chart to support M43.15.
Source · Editorial brief grounded in 4 cited references ↓
- Specify 'thoracolumbar' or 'T12-L1' in the assessment — generic 'spondylolisthesis' maps to M43.10 (unspecified), losing regional specificity and potentially triggering a query.
- Document the grade of slippage (Meyerding Grade I–IV) when available from imaging; while ICD-10 does not capture grade in M43.15, payers and surgical authorizations often require it.
- Record the imaging modality and findings that confirm the listhesis — plain film with flexion-extension views, CT, or MRI — including percent slip or millimeter displacement.
- Note whether the spondylolisthesis is stable or progressive, and any associated neurologic findings (radiculopathy, myelopathy), which may require additional codes such as M54.1x or G99.2.
- Distinguish thoracolumbar from lumbar in the note body, not just the assessment line — auditors cross-reference clinical documentation against the coded region.
Related CPT procedures
Procedure codes commonly billed with M43.15. 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 M43.15 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Defaulting to M43.16 (lumbar) when the documentation says 'lower thoracic/upper lumbar' or 'thoracolumbar junction' — the junction maps to M43.15, not M43.16.
- Confusing M43.15 (spondylolisthesis) with M43.05 (spondylolysis, thoracolumbar) — spondylolysis is a pars defect without forward slip; if slip is documented, use M43.15.
- Coding M43.15 when documentation references an acute traumatic vertebral slip — acute traumatic spondylolisthesis may require an S-category injury code instead, depending on encounter context.
- Using M43.15 as the sole code when neurologic compromise is also documented — radiculopathy or myelopathy at this level requires an additional code to fully capture the clinical picture.
Clinical context
Source · Editorial summary grounded in 4 cited references ↓
M43.15 identifies spondylolisthesis at the thoracolumbar region, distinguishing it from adjacent-level codes M43.14 (thoracic) and M43.16 (lumbar). Use it when the treating provider documents the slip at the thoracolumbar junction specifically — not when the slip is lumbar-dominant or thoracic-dominant. If documentation only says 'spondylolisthesis' without specifying region, default to M43.10 (site unspecified), not M43.15.
Thoracolumbar spondylolisthesis is less common than lumbar-level slippage and often presents after trauma, deformity correction, or in the context of degenerative disease at this transitional zone. The code covers all etiologic subtypes (degenerative, isthmic, traumatic, pathologic) as long as region is documented — no separate code differentiates type within M43.1x. If a congenital or neonatal spondylolisthesis is documented, see the Excludes1 note under M43.1, which excludes acute traumatic slippage coded elsewhere.
This code is recognized by CMS as medically necessary to support chiropractic services (per CMS Article A56273) and is appropriate as a primary or secondary diagnosis on claims for imaging, E/M, physical therapy, pain management, and spinal surgical procedures at the thoracolumbar level.
Sibling codes
Other billable codes under M43.1 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 4 cited references ↓
01What is the thoracolumbar region for ICD-10 coding purposes?
02Does M43.15 differentiate between isthmic, degenerative, and traumatic spondylolisthesis?
03Can M43.15 and M43.05 be coded together on the same claim?
04Is M43.15 valid as a primary diagnosis for surgical authorization?
05What additional codes should I consider alongside M43.15?
06Does CMS recognize M43.15 for chiropractic coverage?
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/M40-M43/M43-/M43.15
- 03cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=56273&ver=26
- 04outsourcestrategies.comhttps://www.outsourcestrategies.com/blog/how-to-document-spondylolisthesis-with-accurate-icd-10-codes/
Mira AI Scribe
Mira's AI scribe captures the clinician's explicit mention of 'thoracolumbar' or 'T12-L1' as the slip location, the imaging source confirming forward vertebral displacement, Meyerding grade if dictated, and any associated neurologic symptoms. This prevents a downcode to M43.10 (unspecified site) and eliminates the audit risk of a region mismatch between the note body and the submitted diagnosis code.
See how Mira captures M43.15 documentation