Is Q66.90 a billable ICD-10-CM code?

Yes. Q66.90 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does Q66.90 sit in the tabular list?

Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Congenital malformations and deformations of the musculoskeletal system (Q65-Q79).

What cannot be coded together with Q66.90?

Q66.90 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 Q66.90 (Q66) and apply to it just the same.

Q66.90

Q66.90 — Congenital deformity of feet, unspecified, unspecified foot

Billable / specific codeICD-10-CMPOA exemptunspecified

Q66.90 is a billable, specific ICD-10-CM code for congenital deformity of feet, unspecified, unspecified foot. It is valid for submission on a claim.

Excludes1 inherited from the categories above Q66.90

These are not written on Q66.90, but they bind it: a note on a category applies to every code beneath it. Billing Q66.90 with anything listed here is a denial.

Written on Q66 — Congenital deformities of feet

reduction defects of feet (Q72.-)
valgus deformities (acquired) (M21.0-)
varus deformities (acquired) (M21.1-)

Other codes that can never be billed with Q66.90

These codes carry an Excludes1 note pointing at Q66.90. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Q66.90 alone.

M20Acquired deformities of fingers and toes

Risk adjustment

Q66.90 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.

Code history

Q66.90 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 Q66.9. If Q66.90 is not quite right, the correct code is usually one of these.

Questions about Q66.90

Is Q66.90 a billable ICD-10-CM code?: Yes. Q66.90 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does Q66.90 sit in the tabular list?: Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Congenital malformations and deformations of the musculoskeletal system (Q65-Q79).
What cannot be coded together with Q66.90?: Q66.90 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 Q66.90 (Q66) and apply to it just the same.