M99
M99 — Biomechanical lesions, not elsewhere classified
Non-billable headerICD-10-CM
M99 is a non-billable header ICD-10-CM code for biomechanical lesions, not elsewhere classified. It cannot be billed on its own: choose one of the more specific child codes below.
Notes
Additional guidance from the ICD-10-CM tabular list.
- This category should not be used if the condition can be classified elsewhere.
Other codes that can never be billed with M99
These codes carry an Excludes1 note pointing at M99. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading M99 alone.
- M43.5Other recurrent vertebral dislocation
Risk adjustment
M99 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Code to one of these instead M99
10 child codes. Green means billable.
- M99.0Segmental and somatic dysfunction
- M99.1Subluxation complex (vertebral)
- M99.2Subluxation stenosis of neural canal
- M99.3Osseous stenosis of neural canal
- M99.4Connective tissue stenosis of neural canal
- M99.5Intervertebral disc stenosis of neural canal
- M99.6Osseous and subluxation stenosis of intervertebral foramina
- M99.7Connective tissue and disc stenosis of intervertebral foramina
- M99.8Other biomechanical lesions
- M99.9Biomechanical lesion, unspecified
Questions about M99
- Is M99 a billable ICD-10-CM code?
- No. M99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
- Where does M99 sit in the tabular list?
- Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Biomechanical lesions, not elsewhere classified (M99).