2026 ICD-10-CM Diagnosis Code M91.10Juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg

ICD-10-CM Codes›M00–M99›M91-M94›M91

ICD-10-CM M91.10
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M91.10 is a billable ICD-10-CM diagnosis code for juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 553 through 554. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified bone disease and musculoskeletal deformities.

Code Identity

ICD-10-CM Code
M91.10
Billable Status
Yes — Valid for Submission
Code Describes
Juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg
Short Description
Juvenile osteochondrosis of head of femur, unspecified leg
Parent Code
M91.1
Juvenile osteochondrosis of head of femur [Legg-Calve-Perthes]

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM91-M94Chondropathies
CategoryM91Juvenile osteochondrosis of hip and pelvis
This CodeM91.10Juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg

Clinical ClassificationClinical

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

CCSR MUS028
Other specified bone disease and musculoskeletal deformities
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Hip Injuries and Disorders

Your hip is the joint where your femur (thigh bone) meets your pelvis (hip bone). There are two main parts: a ball at the end of the femur, which fits in a socket in the pelvis. Your hip is known as a ball-and-socket joint. This is because you have a ball at the end of your femur, and it fits into a socket in your pelvis.

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Convert M91.10 to ICD-9-CMHistory

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

ICD-9-CM
732.1 Juv osteochondros pelvis
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M91.10Overview

Is M91.10 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M91.10 group to?

When juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg is the principal diagnosis on an inpatient stay, it groups to MS-DRG 553, 554, with relative weights from 0.8301 to 1.2963 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M91.10?

Under the General Equivalence Mappings, juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], unspecified leg converts to ICD-9-CM 732.1 (juv osteochondros pelvis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.