Q66.6 ICD-10-CM Code: Other congenital valgus deformities of feet
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0) / Congenital malformations and deformations of the musculoskeletal system (Q65-Q79)
Q66.6
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceOther congenital valgus deformities of feet
A congenital foot deformity present at birth where the foot is turned outward (valgus deformity), not classified as the more specific types.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Congenital metatarsus valgus
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for Q66.6 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for Q66.6 in this effective period.
Excludes 1
Official- reduction defects of feet (Q72.-)
- valgus deformities (acquired) (M21.0-)
- varus deformities (acquired) (M21.1-)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for Q66.6 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for Q66.6 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for Q66.6 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is Q66.6 an HCC code?
No. Q66.6 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
- Code
- Q66.6
- Description
- Other congenital valgus deformities of feet
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
Q66.6 is the ICD-10-CM diagnosis code for other congenital valgus deformities of feet. A congenital foot deformity present at birth where the foot is turned outward (valgus deformity), not classified as the more specific types. Q66.6 sits in the ICD-10-CM chapter for congenital malformations, deformations and chromosomal abnormalities (q00-qa0), within the section covering congenital malformations and deformations of the musculoskeletal system (q65-q79).
Q66.6 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Use this code for valgus deformities that don't fit the calcaneovalgus or pes planus categories.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q66.6 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for valgus deformities that don't fit the calcaneovalgus or pes planus categories
- •Document the specific characteristics of the valgus deformity for clarity