M99.02: Segmental and somatic dysfunction of thoracic region
Region: Subluxation
By Dr. Daniel Turner, DC · Reviewed September 2, 2026
What does M99.02 mean?
M99.02 is the ICD-10-CM code for segmental and somatic dysfunction of the thoracic region, the subluxation code for the mid back.
Searched as thoracic subluxation ICD 10 and M99.02 meaning.
When does a chiropractor use M99.02?
Carries the thoracic component of Medicare claims and disciplines the region count: if 98941 says three regions and the diagnoses show M99.01 and M99.03 only, the claim contradicts itself. Each region billed wants its M99.0 code and its documented findings, and the thoracic region is the one most often billed on autopilot.
Coding rules that matter
- ✓Primary or co primary on Medicare claims where thoracic is among the treated regions
- ✓Backed by thoracic PART findings or imaging in the note
- ✓Paired with the thoracic condition code, most often M54.6
The codes around M99.02
| Code | Description |
|---|---|
| M99.01 | Segmental and somatic dysfunction, cervical |
| M99.02 | Segmental and somatic dysfunction, thoracic (this code) |
| M99.03 | Segmental and somatic dysfunction, lumbar |
| M99.08 | Segmental and somatic dysfunction, rib cage |
When M99.02 is the wrong code
Not for rib and costovertebral dysfunction, which has its own code at M99.08. Not on the claim to justify a region count the note cannot back; the thoracic entry is the one most often added on autopilot and the one reviewers check first when 98941 looks inflated.
How does M99.02 work on Medicare chiropractic claims?
Same statutory footing as the rest of the family: the subluxation is the covered condition. Region agreement between the M99.0 codes, the secondary condition codes, and the CMT region count is precisely what chiropractic claim reviews check first.
Where claims go wrong
Region counts that disagree with the diagnosis list; thoracic entries with no thoracic findings; forgetting the pairing code.
How Cervica helps with M99.02
Cervica validates diagnosis pointers line by line before a claim goes out, checks the Medicare subluxation pairing and region agreement automatically, and carries diagnoses forward from the SOAP note so the claim always matches what the documentation actually says.
Related codes
- →M54.6 · Pain in thoracic spine
- →M99.01 · Segmental and somatic dysfunction of cervical region
- →M99.03 · Segmental and somatic dysfunction of lumbar region
- →98941 · the CPT code this diagnosis most often supports
- →CO-11 · the denial coding mistakes here produce
- →CO-50 · the denial coding mistakes here produce
Quick answers
What does M99.02 mean?
M99.02 is the ICD-10-CM code for segmental and somatic dysfunction of the thoracic region, the subluxation code for the mid back.
When does a chiropractor use M99.02?
Carries the thoracic component of Medicare claims and disciplines the region count: if 98941 says three regions and the diagnoses show M99.01 and M99.03 only, the claim contradicts itself. Each region billed wants its M99.0 code and its documented findings, and the thoracic region is the one most often billed on autopilot.
How does M99.02 work on Medicare chiropractic claims?
Same statutory footing as the rest of the family: the subluxation is the covered condition. Region agreement between the M99.0 codes, the secondary condition codes, and the CMT region count is precisely what chiropractic claim reviews check first.
References
General information for billing teams, not medical, legal, or coding advice for any individual claim. ICD-10-CM is maintained by CMS and the National Center for Health Statistics; the official code set and guidelines control. Payer policies vary.