ICDcodes.org
FY2027

M87.873 — Other osteonecrosis, unspecified ankle

BillableUnspecifiedCC

Is M87.873 billable?

Yes, but M87.873 will trip a Medicare edit. M87.873 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists M87.873 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.

M87.873 at a glance

CodeM87.873
DescriptionOther osteonecrosis, unspecified ankle
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

What Medicare edits apply to M87.873?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name M87.873 directly.

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 M87.873 group to?

M87.873 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, M87.873 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

How is M87.873 listed in the Alphabetic Index?

The Alphabetic Index lists these routes under M87.87, the nearest indexed parent of M87.873. Use them to find the family, then select the specific code.

  • Osteonecrosis › specified type NEC › metatarsus
  • Osteonecrosis › specified type NEC › tarsus
  • Osteonecrosis › specified type NEC › toe

Excludes1 — never code together — inherited from M86-M90

The conditions below can never be reported together with M87.873 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 M87

The conditions below can never be reported together with M87.873 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • juvenile osteonecrosis (M91-M92)
  • osteochondropathies (M90-M93)

Use additional code — inherited from M87

Report an additional code alongside M87.873 to fully describe the condition. M87.873 is sequenced first.

  • code to identify major osseous defect, if applicable (M89.7-)

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M87.873, but a patient may have both at the same time. When documentation supports it, M87.873 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 M87.873 existed?

M87.873 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.

What other codes are in the M87.87 family? (8)