ICD-10-CM 2027 diagnosis code
M99Biomechanical lesions, not elsewhere classified
Not billable — use a more specific code
M99 is a header code, so it can't be reported by itself. Choose one of the 10 more specific codes beneath it.
Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS, effective October 1, 2026. Updated September 29, 2026. About our data
About M99
M99 is the ICD-10-CM diagnosis code for biomechanical lesions, not elsewhere classified. It belongs to 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.
To report this condition, pick the subcode that matches the documentation: M99.0 (dysfunction), M99.1 ((vertebral)), M99.2 (canal), M99.3 (canal), M99.4 (canal), M99.5 (canal), M99.6 (foramina), M99.7 (foramina) 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
- M99.0Segmental and somatic dysfunction
- 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
- M99.1Subluxation complex (vertebral)
- M99.10Subluxation complex (vertebral) of head regionBillable
- M99.11Subluxation complex (vertebral) of cervical regionBillable
- M99.12Subluxation complex (vertebral) of thoracic regionBillable
- M99.13Subluxation complex (vertebral) of lumbar regionBillable
- M99.14Subluxation complex (vertebral) of sacral regionBillable
- M99.15Subluxation complex (vertebral) of pelvic regionBillable
- M99.16Subluxation complex (vertebral) of lower extremityBillable
- M99.17Subluxation complex (vertebral) of upper extremityBillable
- M99.18Subluxation complex (vertebral) of rib cageBillable
- M99.19Subluxation complex (vertebral) of abdomen and other regionsBillable
- M99.2Subluxation stenosis of neural canal
- M99.20Subluxation stenosis of neural canal of head regionBillable
- M99.21Subluxation stenosis of neural canal of cervical regionBillable
- M99.22Subluxation stenosis of neural canal of thoracic regionBillable
- M99.23Subluxation stenosis of neural canal of lumbar regionBillable
- M99.24Subluxation stenosis of neural canal of sacral regionBillable
- M99.25Subluxation stenosis of neural canal of pelvic regionBillable
- M99.26Subluxation stenosis of neural canal of lower extremityBillable
- M99.27Subluxation stenosis of neural canal of upper extremityBillable
- M99.28Subluxation stenosis of neural canal of rib cageBillable
- M99.29Subluxation stenosis of neural canal of abdomen and other regionsBillable
- M99.3Osseous stenosis of neural canal
- M99.30Osseous stenosis of neural canal of head regionBillable
- M99.31Osseous stenosis of neural canal of cervical regionBillable
- M99.32Osseous stenosis of neural canal of thoracic regionBillable
- M99.33Osseous stenosis of neural canal of lumbar regionBillable
- M99.34Osseous stenosis of neural canal of sacral regionBillable
- M99.35Osseous stenosis of neural canal of pelvic regionBillable
- M99.36Osseous stenosis of neural canal of lower extremityBillable
- M99.37Osseous stenosis of neural canal of upper extremityBillable
- M99.38Osseous stenosis of neural canal of rib cageBillable
- M99.39Osseous stenosis of neural canal of abdomen and other regionsBillable
- M99.4Connective tissue stenosis of neural canal
- M99.40Connective tissue stenosis of neural canal of head regionBillable
- M99.41Connective tissue stenosis of neural canal of cervical regionBillable
- M99.42Connective tissue stenosis of neural canal of thoracic regionBillable
- M99.43Connective tissue stenosis of neural canal of lumbar regionBillable
- M99.44Connective tissue stenosis of neural canal of sacral regionBillable
- M99.45Connective tissue stenosis of neural canal of pelvic regionBillable
- M99.46Connective tissue stenosis of neural canal of lower extremityBillable
- M99.47Connective tissue stenosis of neural canal of upper extremityBillable
- M99.48Connective tissue stenosis of neural canal of rib cageBillable
- M99.49Connective tissue stenosis of neural canal of abdomen and other regionsBillable
- M99.5Intervertebral disc stenosis of neural canal
- M99.50Intervertebral disc stenosis of neural canal of head regionBillable
- M99.51Intervertebral disc stenosis of neural canal of cervical regionBillable
- M99.52Intervertebral disc stenosis of neural canal of thoracic regionBillable
- M99.53Intervertebral disc stenosis of neural canal of lumbar regionBillable
- M99.54Intervertebral disc stenosis of neural canal of sacral regionBillable
- M99.55Intervertebral disc stenosis of neural canal of pelvic regionBillable
- M99.56Intervertebral disc stenosis of neural canal of lower extremityBillable
- M99.57Intervertebral disc stenosis of neural canal of upper extremityBillable
- M99.58Intervertebral disc stenosis of neural canal of rib cageBillable
- M99.59Intervertebral disc stenosis of neural canal of abdomen and other regionsBillable
- M99.6Osseous and subluxation stenosis of intervertebral foramina
- M99.60Osseous and subluxation stenosis of intervertebral foramina of head regionBillable
- M99.61Osseous and subluxation stenosis of intervertebral foramina of cervical regionBillable
- M99.62Osseous and subluxation stenosis of intervertebral foramina of thoracic regionBillable
- M99.63Osseous and subluxation stenosis of intervertebral foramina of lumbar regionBillable
- M99.64Osseous and subluxation stenosis of intervertebral foramina of sacral regionBillable
- M99.65Osseous and subluxation stenosis of intervertebral foramina of pelvic regionBillable
- M99.66Osseous and subluxation stenosis of intervertebral foramina of lower extremityBillable
- M99.67Osseous and subluxation stenosis of intervertebral foramina of upper extremityBillable
- M99.68Osseous and subluxation stenosis of intervertebral foramina of rib cageBillable
- M99.69Osseous and subluxation stenosis of intervertebral foramina of abdomen and other regionsBillable
- M99.7Connective tissue and disc stenosis of intervertebral foramina
- M99.70Connective tissue and disc stenosis of intervertebral foramina of head regionBillable
- M99.71Connective tissue and disc stenosis of intervertebral foramina of cervical regionBillable
- M99.72Connective tissue and disc stenosis of intervertebral foramina of thoracic regionBillable
- M99.73Connective tissue and disc stenosis of intervertebral foramina of lumbar regionBillable
- M99.74Connective tissue and disc stenosis of intervertebral foramina of sacral regionBillable
- M99.75Connective tissue and disc stenosis of intervertebral foramina of pelvic regionBillable
- M99.76Connective tissue and disc stenosis of intervertebral foramina of lower extremityBillable
- M99.77Connective tissue and disc stenosis of intervertebral foramina of upper extremityBillable
- M99.78Connective tissue and disc stenosis of intervertebral foramina of rib cageBillable
- M99.79Connective tissue and disc stenosis of intervertebral foramina of abdomen and other regionsBillable
- M99.8Other biomechanical lesions
- M99.80Other biomechanical lesions of head regionBillable
- M99.81Other biomechanical lesions of cervical regionBillable
- M99.82Other biomechanical lesions of thoracic regionBillable
- M99.83Other biomechanical lesions of lumbar regionBillable
- M99.84Other biomechanical lesions of sacral regionBillable
- M99.85Other biomechanical lesions of pelvic regionBillable
- M99.86Other biomechanical lesions of lower extremityBillable
- M99.87Other biomechanical lesions of upper extremityBillable
- M99.88Other biomechanical lesions of rib cageBillable
- M99.89Other biomechanical lesions of abdomen and other regionsBillable
- M99.9Biomechanical lesion, unspecifiedBillable
Coding notes
Note
- This category should not be used if the condition can be classified elsewhere.
Notes that apply from higher levels
Instructions written at a parent level also apply to M99.
Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.
Codes whose notes reference M99
- M43.5Excludes1
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
Is M99 billable?
- No. M99 is a header code. Report one of its more specific subcodes instead.