ICD-10-CM 2027 diagnosis code
M99.0Segmental and somatic dysfunction
M99.0 is a header code, so it can't be reported by itself. Choose one of the 10 more specific codes beneath it.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About M99.0
M99.0 is the ICD-10-CM diagnosis code for segmental and somatic dysfunction. It belongs to category M99 (biomechanical lesions, not elsewhere classified), block M99 (biomechanical lesions, not elsewhere classified) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 10 subcodes must be used instead.
Within M99 (biomechanical lesions, not elsewhere classified), M99.0 is specifically for segmental and somatic dysfunction. Related codes cover subluxation complex (vertebral) (M99.1), subluxation stenosis of neural canal (M99.2), osseous stenosis of neural canal (M99.3), connective tissue stenosis of neural canal (M99.4), intervertebral disc stenosis of neural canal (M99.5), osseous and subluxation stenosis of intervertebral foramina (M99.6), connective tissue and disc stenosis of intervertebral foramina (M99.7), other biomechanical lesions (M99.8) and 1 more.
To report this condition, pick the subcode that matches the documentation: M99.00 (of head region), M99.01 (of cervical region), M99.02 (of thoracic region), M99.03 (of lumbar region), M99.04 (of sacral region), M99.05 (of pelvic region), M99.06 (of lower extremity), M99.07 (of upper extremity) and 2 more.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under M99.0
- M99.00Segmental and somatic dysfunction of head regionBillable
- M99.01Segmental and somatic dysfunction of cervical regionBillable
- M99.02Segmental and somatic dysfunction of thoracic regionBillable
- M99.03Segmental and somatic dysfunction of lumbar regionBillable
- M99.04Segmental and somatic dysfunction of sacral regionBillable
- M99.05Segmental and somatic dysfunction of pelvic regionBillable
- M99.06Segmental and somatic dysfunction of lower extremityBillable
- M99.07Segmental and somatic dysfunction of upper extremityBillable
- M99.08Segmental and somatic dysfunction of rib cageBillable
- M99.09Segmental and somatic dysfunction of abdomen and other regionsBillable
Notes that apply from higher levels
Instructions written at a parent level also apply to M99.0.
› From M99 Biomechanical lesions, not elsewhere classified
- This category should not be used if the condition can be classified elsewhere.
Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about M99.0
Is M99.0 billable?
- No. M99.0 is a header code. Report one of its more specific subcodes instead.