ICD-10-CM 2027 diagnosis code
Q66.80Congenital vertical talus deformity, unspecified foot
Q66.80 is a valid, billable ICD-10-CM code for congenital vertical talus deformity, unspecified foot. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Looking up by condition? See ICD-10 code for Vertical talus, ICD-10 code for Vertical talus congenital deformity.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About Q66.80
Q66.80 is the ICD-10-CM diagnosis code for congenital vertical talus deformity, unspecified foot. It belongs to category Q66 (congenital deformities of feet), block Q65-Q79 (congenital malformations and deformations of the musculoskeletal system) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within Q66.8, choose Q66.80 (Congenital vertical talus deformity, unspecified foot) only when documentation doesn't support a more specific option: congenital vertical talus deformity, right foot (Q66.81), congenital vertical talus deformity, left foot (Q66.82) and other specified congenital deformities of feet (Q66.89).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 564 (Other Musculoskeletal System and Connective Tissue Diagnoses with MCC, relative weight 1.4908), DRG 565 (Other Musculoskeletal System and Connective Tissue Diagnoses with CC, relative weight 0.9783), DRG 566 (Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCC, relative weight 0.7378) and DRG 795 (Normal Newborn, relative weight 0.2022), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 754.61 (congenital pes planus).
Notes that apply from higher levels
Instructions written at a parent level also apply to Q66.80.
Broader instructions also apply from Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to Q66.80.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 08 · Diseases and Disorders of the Musculoskeletal System and Connective Tissue
MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
ICD-9-CM equivalent
Converter →- 754.61Congenital pes planusapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about Q66.80
Is Q66.80 billable?
- Yes. Q66.80 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q66.80 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q66.80 as a principal diagnosis.
Is Q66.80 a CC or MCC?
- No. Q66.80 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does Q66.80 group to?
- Q66.80 is used in the MS-DRG v44.0 logic for MS-DRG 564 (Other Musculoskeletal System and Connective Tissue Diagnoses with MCC), MS-DRG 565 (Other Musculoskeletal System and Connective Tissue Diagnoses with CC), MS-DRG 566 (Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCC) and MS-DRG 795 (Normal Newborn). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for Q66.80?
- The CMS General Equivalence Mappings map Q66.80 to ICD-9-CM 754.61.