M90.549 — Osteonecrosis in diseases classified elsewhere, unspecified hand
Is M90.549 billable?
Yes, but M90.549 will trip a Medicare edit. M90.549 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists M90.549 under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
M90.549 at a glance
| Code | M90.549 |
|---|---|
| Description | Osteonecrosis in diseases classified elsewhere, unspecified hand |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
What Medicare edits apply to M90.549?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name M90.549 directly.
This code describes a manifestation of an underlying disease. The underlying condition must be sequenced before it, so it can never be the principal or first-listed diagnosis.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does M90.549 group to?
M90.549 sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 553Bone Diseases and Arthropathies with MCCmedical
- 554Bone Diseases and Arthropathies without MCCmedical
As a secondary diagnosis, M90.549 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is M90.549 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under M90.54, the nearest indexed parent of M90.549. Use them to find the family, then select the specific code.
- Osteonecrosis › secondary NEC › due to › hemoglobinopathy NEC › carpus
- Osteonecrosis › secondary NEC › due to › hemoglobinopathy NEC › finger
- Osteonecrosis › secondary NEC › due to › hemoglobinopathy NEC › metacarpus
- Osteonecrosis › secondary NEC › in › caisson disease › carpus
- Osteonecrosis › secondary NEC › in › caisson disease › finger
- Osteonecrosis › secondary NEC › in › caisson disease › metacarpus
Excludes1 — never code together — inherited from M86-M90
The conditions below can never be reported together with M90.549 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- postprocedural osteopathies (M96.-)
Excludes1 — never code together — inherited from M90
The conditions below can never be reported together with M90.549 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Code first — inherited from M90.5
The underlying condition below must be sequenced before M90.549. M90.549 describes a manifestation and cannot be the principal or first-listed diagnosis.
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M90.549, but a patient may have both at the same time. When documentation supports it, M90.549 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)
How long has M90.549 existed?
M90.549 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.