M26.659 — Arthropathy of unspecified temporomandibular joint
Is M26.659 billable?
Yes, but M26.659 is an unspecified code. M26.659 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, M26.659 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting M26.659 — the more specific alternatives are listed below.
M26.659 at a glance
| Code | M26.659 |
|---|---|
| Description | Arthropathy of unspecified temporomandibular joint |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does M26.659 group to?
M26.659 sits in MDC Pre and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 011Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCCsurgical
- 012Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CCsurgical
- 013Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCCsurgical
How is M26.659 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under M26.65, the nearest indexed parent of M26.659. Use them to find the family, then select the specific code.
- Arthropathy › temporomandibular joint
Excludes1 — never code together — inherited from M26-M27
The conditions below can never be reported together with M26.659 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M26.659, but a patient may have both at the same time. When documentation supports it, M26.659 and the excluded code may both be reported.
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Excludes2 — not included here — inherited from M26.6
The conditions below are not part of M26.659, but a patient may have both at the same time. When documentation supports it, M26.659 and the excluded code may both be reported.
How long has M26.659 existed?
M26.659 first appears in FY2021 (FY2020 is not available, so it may have appeared then).
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.