2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q70.4 is a billable ICD-10-CM diagnosis code for polysyndactyly, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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 the other POA exempt codes in Congenital malformations and deformations of the musculoskeletal system (Q65-Q79).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Congenital hallux varus
  • Crossed polysyndactyly
  • Greig cephalopolysyndactyly, contiguous gene syndrome
  • 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
  • Polysyndactyly of great toe
  • Polysyndactyly of little toe
  • Tibial hemimelia, polysyndactyly, triphalangeal thumb syndrome
  • Triphalangeal thumb
  • Triphalangeal thumb and polysyndactyly syndrome
  • Varus deformity of great toe

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q70.4: its own notes plus those printed at Chapter 17. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

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

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • inborn errors of metabolism (E70-E88)

Notes

General instructions on how these codes are used.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • Codes from this chapter are not for use on maternal records

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Q70.4, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming Q70.4: they are not reported together with it, unless the two conditions are unrelated.

  • Q74 Other congenital malformations of limb(s)
    syndactyly (Q70.-) names Q70.-, which includes this code
  • M20 Acquired deformities of fingers and toes
    congenital deformities and malformations of fingers and toes (Q66.-, Q68-Q70, Q74.-) names Q68-Q70, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

  • Polysyndactyly

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

  • Syndactyly

    a congenital anomaly of the hand or foot, marked by the webbing between adjacent fingers or toes. syndactylies are classified as complete or incomplete by the degree of joining. syndactylies can also be simple or complex. simple syndactyly indicates joining of only skin or soft tissue; complex syndactyly marks joining of bony elements.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Q70.4Overview

What is the ICD-10 code for polysyndactyly, unspecified?

The ICD-10-CM code for polysyndactyly, unspecified is Q70.4 (sometimes written as Q704). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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, 566, 565, with relative weights from 0.7374 to 1.4909 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. The code appears in the Congenital malformations and deformations of the musculoskeletal system (Q65-Q79) range of the CMS exempt list.

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.