Is M21.522 a billable ICD-10-CM code?

Yes. M21.522 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does M21.522 sit in the tabular list?

Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Other joint disorders (M20-M25).

What cannot be coded together with M21.522?

M21.522 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M21.522 (M21.5, M21) and apply to it just the same.

M21.522

M21.522 — Acquired clubhand, left hand

Billable / specific codeICD-10-CMleft

M21.522 is a billable, specific ICD-10-CM code for acquired clubhand, left hand. It is valid for submission on a claim.

Excludes1 inherited from the categories above M21.522

These are not written on M21.522, but they bind it: a note on a category applies to every code beneath it. Billing M21.522 with anything listed here is a denial.

Written on M21.5 — Acquired clawhand, clubhand, clawfoot and clubfoot

clubfoot, not specified as acquired (Q66.89)

Written on M21 — Other acquired deformities of limbs

acquired absence of limb (Z89.-)
congenital absence of limbs (Q71-Q73)
congenital deformities and malformations of limbs (Q65-Q66, Q68-Q74)

Excludes2 inherited from the categories above M21.522

Also inherited, and the opposite of Excludes1: these conditions are not part of M21.522, but a patient can have both, so you may code both.

Written on M21 — Other acquired deformities of limbs

acquired deformities of fingers or toes (M20.-)
coxa plana (M91.2)

Other codes that can never be billed with M21.522

These codes carry an Excludes1 note pointing at M21.522. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading M21.522 alone.

M23Internal derangement of knee

Risk adjustment

M21.522 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

M21.522 is named in 11 Medicare coverage policies — 4 listing it as supporting medical necessity, and 7 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A58865Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
A58883Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
A58893Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
A59374Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered

Code history

M21.522 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share M21.52. If M21.522 is not quite right, the correct code is usually one of these.

Questions about M21.522

Is M21.522 a billable ICD-10-CM code?: Yes. M21.522 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does M21.522 sit in the tabular list?: Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Other joint disorders (M20-M25).
What cannot be coded together with M21.522?: M21.522 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M21.522 (M21.5, M21) and apply to it just the same.