2026 ICD-10-CM Diagnosis Code Q70.4Polysyndactyly, unspecified

ICD-10-CM Codes›Q00-Q99›Q65-Q79›Q70

ICD-10-CM Q70.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q70.4 is a billable ICD-10-CM diagnosis code for polysyndactyly, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Musculoskeletal congenital conditions.

Code Identity

ICD-10-CM Code
Q70.4
Billable Status
Yes — Valid for Submission
Code Describes
Polysyndactyly, unspecified
Short Description
Polysyndactyly, unspecified
Same as the full description in the CMS dataset.
Parent Code
Q70
Syndactyly

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ65-Q79Congenital malformations and deformations of the musculoskeletal system
CategoryQ70Syndactyly
This CodeQ70.4Polysyndactyly, unspecified

Present on Admission (POA)Billing

Q70.4 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Congenital hallux varus
  • Crossed polysyndactyly
  • Hallux varus, preaxial polysyndactyly syndrome
  • Hamartoma of tongue
  • Heart defect, tongue hamartoma, polysyndactyly syndrome
  • Hyperphalangy
  • Mirror hands and feet co-occurrent with nasal defect
  • Polysyndactyly
  • Tibial hemimelia, polysyndactyly, triphalangeal thumb syndrome
  • Triphalangeal thumb
  • Triphalangeal thumb and polysyndactyly syndrome
  • Varus deformity of great toe

Tabular List NotesGuidance

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

Type 1 Excludes

  • specified syndactyly of hand and feet - code to specified conditions Q70.0 Q70.3

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Polysyndactyly

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MAL008
Musculoskeletal congenital conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • GLI3 Gene|GLI-Kruppel Family Member GLI3 (Greig Cephalopolysyndactyly Syndrome) Gene|GLI3|GLI3

    this gene plays a regulatory role in limb development and is involved in sonic hedgehog signal transduction.

  • GLI3 wt Allele|GCPS|GLI-Kruppel Family Member 3|GLI-Kruppel Family Member GLI3 (Greig Cephalopolysyndactyly Syndrome) wt Allele|GLI3|PAP-A|PAPA|PHS

    human gli3 wild-type allele is located in the vicinity of 7p13 and is approximately 272 kb in length. this allele, which encodes zinc finger protein gli3, plays a role in the regulation of sonic hedgehog-dependent transcription of specific genes during the development of multiple organ systems. this gene is the site of a mutation that is linked to greig cephalopolysyndactyly syndrome.

  • Greig Syndrome|GCPS|Greig Cephalopolysyndactyly Syndrome|Greig Cephalosyndactyly Syndrome|Greig's Syndrome

    an autosomal dominant genetic disorder caused by mutations in the gli3 gene. it is characterized by physical abnormalities of the fingers and/or toes (extra fingers and/ or toes, fusion of the fingers and/or toes), large size head with prominent forehead and hypertelorism.

  • Polysyndactyly

    a rare anatomical malformation characterized by polydactyly (extra fingers or toes) and syndactyly (webbed fingers or toes).

  • Type II Acrocephalopolysyndactyly|Acrocephalopolysyndactyly Type II|Acrocephalopolysyndactyly Type II|Carpenter 's Syndrome|Carpenter Syndrome|Carpenter Syndrome

    an extremely rare autosomal recessive syndrome characterized by premature closure of cranial sutures leading to cone-shaped head, fusion of the digits, and the presence of more digits than normal. it may be associated with heart defects, single horseshoe-shaped kidney, short stature, undescended testes, and mild mental retardation.

  • GLI3 wt Allele|ACLS|GCPS|GCPS-190|GLI-Kruppel Family Member 3|GLI-Kruppel Family Member GLI3 (Greig Cephalopolysyndactyly Syndrome) wt Allele|GLI3FL|PAP-A|PAPA|PAPA1|PAPB|PHS|PPDIV

    human gli3 wild-type allele is located in the vicinity of 7p13 and is approximately 272 kb in length. this allele, which encodes zinc finger protein gli3, plays a role in the regulation of sonic hedgehog-dependent transcription of specific genes during the development of multiple organ systems. this gene is the site of a mutation that is linked to greig cephalopolysyndactyly syndrome.

  • Type II Acrocephalopolysyndactyly|Acrocephalopolysyndactyly Type II|Acrocephalopolysyndactyly Type II|Carpenter Syndrome|Carpenter Syndrome|Carpenter's Syndrome

    an extremely rare autosomal recessive syndrome characterized by premature closure of cranial sutures leading to cone-shaped head, fusion of the digits, and the presence of more digits than normal. it may be associated with heart defects, single horseshoe-shaped kidney, short stature, undescended testes, and mild mental retardation.

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.

Convert Q70.4 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
755.00 Polydactyly NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
755.10 Syndactyly, multiple/NOS
Approximate The match is approximate rather than exact.

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 Q70.4Overview

Is Q70.4 (Syndactyly) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report polysyndactyly, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Q70.4 group to?

When polysyndactyly, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q70.4 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for polysyndactyly, unspecified on inpatient claims.

What is the ICD-9 equivalent of Q70.4?

Under the General Equivalence Mappings, polysyndactyly, unspecified converts to ICD-9-CM 755.00 (polydactyly NOS) and 755.10 (syndactyly, multiple/NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.