2026 ICD-10-CM Diagnosis Code Q66Congenital deformities of feet

ICD-10-CM Codes›Q00-Q99›Q65-Q79›Q66

ICD-10-CM Q66
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q66 is a non-billable ICD-10-CM category code for congenital deformities of feet, so it cannot be submitted on claims. Use a more specific code from this category instead, such as Q66.00, Q66.01, Q66.02, and Q66.10.

Code Identity

ICD-10-CM Code
Q66
Billable Status
No — Non-Billable Category
Code Describes
Congenital deformities of feet
Chapter
Q65-Q79
Congenital malformations and deformations of the musculoskeletal system

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ65-Q79Congenital malformations and deformations of the musculoskeletal system
CategoryQ66Congenital deformities of feet
This CodeQ66Congenital deformities of feet

Specific Coding for Congenital deformities of feetOverview

Non-specific codes like Q66 require more characters. Use one of these billable codes instead:

  • Q66.0 for Congenital talipes equinovarus

  • Use Q66.00 for Congenital talipes equinovarus, unspecified foot

  • Use Q66.01 for Congenital talipes equinovarus, right foot

  • Use Q66.02 for Congenital talipes equinovarus, left foot

  • Q66.1 for Congenital talipes calcaneovarus

  • Use Q66.10 for Congenital talipes calcaneovarus, unspecified foot

  • Use Q66.11 for Congenital talipes calcaneovarus, right foot

  • Use Q66.12 for Congenital talipes calcaneovarus, left foot

  • Q66.2 for Congenital metatarsus (primus) varus

  • Q66.21 for Congenital metatarsus primus varus

  • Q66.22 for Congenital metatarsus adductus

  • Q66.3 for Other congenital varus deformities of feet

  • Use Q66.30 for Other congenital varus deformities of feet, unspecified foot

  • Use Q66.31 for Other congenital varus deformities of feet, right foot

  • Use Q66.32 for Other congenital varus deformities of feet, left foot

  • Q66.4 for Congenital talipes calcaneovalgus

  • Use Q66.40 for Congenital talipes calcaneovalgus, unspecified foot

  • Use Q66.41 for Congenital talipes calcaneovalgus, right foot

  • Use Q66.42 for Congenital talipes calcaneovalgus, left foot

  • Q66.5 for Congenital pes planus

  • Use Q66.50 for Congenital pes planus, unspecified foot

  • Use Q66.51 for Congenital pes planus, right foot

  • Use Q66.52 for Congenital pes planus, left foot

  • Use Q66.6 for Other congenital valgus deformities of feet

  • Q66.7 for Congenital pes cavus

  • Use Q66.70 for Congenital pes cavus, unspecified foot

  • Use Q66.71 for Congenital pes cavus, right foot

  • Use Q66.72 for Congenital pes cavus, left foot

  • Q66.8 for Other congenital deformities of feet

  • Use Q66.80 for Congenital vertical talus deformity, unspecified foot

  • Use Q66.81 for Congenital vertical talus deformity, right foot

  • Use Q66.82 for Congenital vertical talus deformity, left foot

  • Use Q66.89 for Other specified congenital deformities of feet

  • Q66.9 for Congenital deformity of feet, unspecified

  • Use Q66.90 for Congenital deformity of feet, unspecified, unspecified foot

  • Use Q66.91 for Congenital deformity of feet, unspecified, right foot

  • Use Q66.92 for Congenital deformity of feet, unspecified, left foot

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • reduction defects of feet Q72
  • valgus deformities acquired M21.0
  • varus deformities acquired M21.1

Patient EducationClinical

Birth Defects

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

The full article covers:

  • What are birth defects?
  • What causes birth defects?
  • Who is at risk of having a baby with birth defects?
  • How are birth defects diagnosed?
  • What are the treatments for birth defects?
  • Can birth defects be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Q66Overview

Is Q66 (Congenital deformities of feet) a billable code?

No. This is a category header that groups the codes for congenital deformities of feet, and headers cannot be submitted on claims. Claims for congenital deformities of feet need a more specific code from this category, such as Q66.00, Q66.01, and Q66.02.