M91.1 – Juvenile osteochondrosis of head of femur [Legg-Calve-Perthes]

ICD-10-CM 2027 diagnosis code · Chondropathies

Non-billable header

ICD-10-CM code M91.1

Code: M91.1 (claims format: M911)
Description: Juvenile osteochondrosis of head of femur [Legg-Calve-Perthes]
Short description: Juvenile osteochondrosis of head of femur
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block: M91-M94 Chondropathies
Parent codes: M91

Billable codes under M91.1

M91.1 is a header code and cannot be used on claims. Choose the most specific code:

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

M91 – Juvenile osteochondrosis of hip and pelvis

Excludes1 (not coded here):

slipped upper femoral epiphysis (nontraumatic) (M93.0-)

Block M91-M94

Excludes1 (not coded here):

postprocedural chondropathies (M96.-)

Index terms for M91.1

Entries in the ICD-10-CM alphabetic index that lead to this code:

Legg

Related codes in M91

M91.0 – Juvenile osteochondrosis of pelvisBillable
M91.2 – Coxa planaHeader
M91.3 – PseudocoxalgiaHeader
M91.4 – Coxa magnaHeader
M91.8 – Other juvenile osteochondrosis of hip and pelvisHeader
M91.9 – Juvenile osteochondrosis of hip and pelvis, unspecifiedHeader

Frequently asked questions

What is ICD-10 code M91.1?

M91.1 is the ICD-10-CM code for juvenile osteochondrosis of head of femur [Legg-Calve-Perthes], in the block M91-M94 (Chondropathies).

Is M91.1 a billable code?

No. M91.1 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M91.1 belong to?

It belongs to category M91 – Juvenile osteochondrosis of hip and pelvis.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.