2027 ICD-10-CM Diagnosis Code M87.163Osteonecrosis due to drugs, unspecified tibia

ICD-10-CM Codes›M00–M99›M86-M90›M87

ICD-10-CM M87.163
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M87.163 is a billable ICD-10-CM diagnosis code for osteonecrosis due to drugs, unspecified tibia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 553 through 554. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 217 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as osteonecrosis of tibia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Aseptic necrosis and osteonecrosis and Drug induced or toxic related condition.

M87.163 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 39 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 39, ESRD (V21) category 39, ESRD (V24) category 39, and RxHCC Part D (V08) category 80 for payment year 2027.

Code Identity

ICD-10-CM Code
M87.163
Billable Status
Yes — Valid for Submission
Code Describes
Osteonecrosis due to drugs, unspecified tibia
Short Description
Osteonecrosis due to drugs, unspecified tibia
Same as the full description in the CMS dataset.
Parent Code
M87.16
Osteonecrosis due to drugs, tibia and fibula

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM86-M90Other osteopathies
CategoryM87Osteonecrosis
This CodeM87.163Osteonecrosis due to drugs, unspecified tibia

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M87.163.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Medicare Risk Adjustment (HCC)Billing

M87.163 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 39
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 39 · ESRD (V21): HCC 39 · ESRD (V24): HCC 39
ESRD V21 weights: 0.061 dialysis, 0.375–0.468 functioning graft · ESRD V24 weights: 0.092 dialysis, 0.431–0.578 functioning graft
Part D (RxHCC)
RxHCC 80 — Aseptic Necrosis of Bone
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Osteonecrosis of tibia
  • Osteonecrosis of tibia caused by drug

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M87.163: its own notes plus those printed at M87.1, M87, block M86-M90, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From M87 Osteonecrosis applies to 217 codes
  • avascular necrosis of bone

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From M87 Osteonecrosis applies to 217 codes
  • juvenile osteonecrosis (M91-M92)
  • osteochondropathies (M90-M93)
From Block M86-M90 Other osteopathies applies to 732 codes
  • postprocedural osteopathies (M96.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • 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)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From M87.1 Osteonecrosis due to drugs applies to 44 codes
  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
From M87 Osteonecrosis applies to 217 codes
  • code to identify major osseous defect, if applicable (M89.7-)

Notes

General instructions on how these codes are used.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M87.163, its category, or a range that includes it.

Code First 2

These codes say to code first a condition named in the note, and M87.163 is one of the conditions named.

  • M89.7 Major osseous defect
    aseptic necrosis of bone (M87.-) names M87.-, which includes this code
  • M89.7 Major osseous defect
    osteonecrosis (M87.-) names M87.-, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS030
Aseptic necrosis and osteonecrosis
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ030
Drug induced or toxic related condition
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Osteonecrosis

    death of a bone or part of a bone, either atraumatic or posttraumatic.

Patient EducationClinical

Osteonecrosis

Osteonecrosis is a disease caused by reduced blood flow to bones in the joints. In people with healthy bones, new bone is always replacing old bone. In osteonecrosis, the lack of blood causes the bone to break down faster than the body can make enough new bone. The bone starts to die and may break down.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert M87.163 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
733.49 Asept necrosis bone NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About M87.163Overview

What is the ICD-10 code for osteonecrosis due to drugs, unspecified tibia?

The ICD-10-CM code for osteonecrosis due to drugs, unspecified tibia is M87.163 (sometimes written as M87163). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M87.163 (Osteonecrosis due to drugs, tibia and fibula) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report osteonecrosis due to drugs, unspecified tibia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does M87.163 group to?

When osteonecrosis due to drugs, unspecified tibia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 554, 553, with relative weights from 0.8328 to 1.2492 depending on complications. Higher weights mean higher Medicare reimbursement.

Is M87.163 a CC or MCC?

CMS lists M87.163 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 217 closely related codes in its exclusion list.

Can M87.163 be reported with a code from M96?

Not as a rule. The Excludes1 note at block M86-M90, which applies to M87.163, lists "postprocedural osteopathies (M96.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does M87.163 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. M87.163 mapped to HCC 39 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 39 (Bone/Joint/Muscle Infections/Necrosis), ESRD (V21) category 39 (Bone/Joint/Muscle Infections/Necrosis), ESRD (V24) category 39 (Bone/Joint/Muscle Infections/Necrosis), and RxHCC Part D (V08) category 80 (Aseptic Necrosis of Bone).