M90.50 — Osteonecrosis in diseases classified elsewhere, unspecified site

BillableUnspecifiedCC

Is M90.50 billable?

Yes, but M90.50 will trip a Medicare edit. M90.50 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists M90.50 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.

More specific alternatives

M90.50 at a glance

Code	M90.50
Description	Osteonecrosis in diseases classified elsewhere, unspecified site
Billable	Yes
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027

What Medicare edits apply to M90.50?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name M90.50 directly.

Manifestation code — never sequenced first — MCE edit 6

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.

Unspecified — a laterality-specific code exists — MCE edit 20

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 M90.50 group to?

M90.50 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, M90.50 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

How is M90.50 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to M90.50. They show the wording a clinician may have documented, which often differs from the Tabular description.

Osteonecrosis › secondary NEC › due to › hemoglobinopathy NEC
Osteonecrosis › secondary NEC › in › caisson disease

Excludes1 — never code together — inherited from M86-M90

The conditions below can never be reported together with M90.50 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 M90.50 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

osteochondritis, osteomyelitis, and osteopathy (in):
cryptococcosis (B45.3)
diabetes mellitus (E08-E13 with .69-)
gonococcal (A54.43)
neurogenic syphilis (A52.11)
renal osteodystrophy (N25.0)
salmonellosis (A02.24)
secondary syphilis (A51.46)
syphilis (late) (A52.77)

Code first — inherited from M90.5

The underlying condition below must be sequenced before M90.50. M90.50 describes a manifestation and cannot be the principal or first-listed diagnosis.

underlying disease, such as:
caisson disease (T70.3)
hemoglobinopathy (D50-D64)

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M90.50, but a patient may have both at the same time. When documentation supports it, M90.50 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 M90.50 existed?

M90.50 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.