M20.1 – Hallux valgus (acquired)

ICD-10-CM 2027 diagnosis code · Other joint disorders

Non-billable header

ICD-10-CM code M20.1

Code: M20.1 (claims format: M201)
Description: Hallux valgus (acquired)
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: M20-M25 Other joint disorders
Parent codes: M20

Billable codes under M20.1

M20.1 is a header code and cannot be used on claims. Choose the most specific code:

M20.10 – Hallux valgus (acquired), unspecified footBillable
M20.11 – Hallux valgus (acquired), right footBillable
M20.12 – Hallux valgus (acquired), left footBillable

Notes for M20.1

Excludes2 (not included here):

bunion (M21.6-)

Notes inherited from parent codes

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

M20 – Acquired deformities of fingers and toes

Excludes1 (not coded here):

acquired absence of fingers and toes (Z89.-)
congenital absence of fingers and toes (Q71.3-, Q72.3-)
congenital deformities and malformations of fingers and toes (Q66.-, Q68-Q70, Q74.-)

Block M20-M25

Excludes2 (not included here):

joints of the spine (M40-M54)

Index terms for M20.1

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

Related codes in M20

M20.0 – Deformity of finger(s)Header
M20.2 – Hallux rigidusHeader
M20.3 – Hallux varus (acquired)Header
M20.4 – Other hammer toe(s) (acquired)Header
M20.5 – Other deformities of toe(s) (acquired)Header
M20.6 – Acquired deformities of toe(s), unspecifiedHeader

Frequently asked questions

What is ICD-10 code M20.1?

M20.1 is the ICD-10-CM code for hallux valgus (acquired), in the block M20-M25 (Other joint disorders).

Is M20.1 a billable code?

No. M20.1 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M20.1 belong to?

It belongs to category M20 – Acquired deformities of fingers and toes.

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.