2026 ICD-10-CM Diagnosis Code Q84.4Congenital leukonychia

ICD-10-CM Codes›Q00-Q99›Q80-Q89›Q84

ICD-10-CM Q84.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q84.4 is a billable ICD-10-CM diagnosis code for congenital leukonychia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified congenital anomalies.

Code Identity

ICD-10-CM Code
Q84.4
Billable Status
Yes — Valid for Submission
Code Describes
Congenital leukonychia
Short Description
Congenital leukonychia
Same as the full description in the CMS dataset.
Parent Code
Q84
Other congenital malformations of integument

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ80-Q89Other congenital malformations
CategoryQ84Other congenital malformations of integument
This CodeQ84.4Congenital leukonychia

Present on Admission (POA)Billing

Q84.4 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.

  • Angular cheilitis
  • Circumscribed palmoplantar keratoderma
  • Congenital leukonychia
  • FLOTCH syndrome
  • Focal acral hyperkeratosis
  • Genetic syndrome with hypermelanosis
  • Knuckle pads
  • Knuckle pads, leukonychia, sensorineural deafness, palmoplantar hyperkeratosis syndrome
  • Leukonychia totalis
  • Leukonychia totalis, acanthosis-nigricans-like lesions, abnormal hair syndrome
  • PLACK syndrome
  • Punctate palmoplantar keratoderma
  • Trichilemmal cyst

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.

    • Leukonychia(punctata) (striata)
      • congenital
    • Leukopathia unguium
      • congenital

Clinical ClassificationClinical

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

CCSR MAL010
Other specified and unspecified congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Knuckle Pads

    benign skin fibromas, typically occurring over the small joints of the hands and feet, that are associated with repetitive friction or pressure.

  • Bart-Pumphrey Syndrome|Knuckle Pads, Leukonychia and Sensorineural Deafness|Knuckle pads, leuconychia and deafness

    a rare autosomal dominant condition caused by mutation(s) in the gjb2 gene, encoding gap junction beta-2 protein (connexin-26). this condition is characterized by sensorineural hearing loss, hyperkeratotic plaques on finger joints (knuckle pads), and white discoloration of nails (leukonychia) and may also be associated with palmoplantar keratoderma.

Patient EducationClinical

Nail Diseases

Your toenails and fingernails protect the tissues of your toes and fingers. They are made up of layers of a hardened protein called keratin, which is also in your hair and skin. The health of your nails can be a clue to your overall health. Healthy nails are usually smooth and consistent in color.

Read the full article at MedlinePlus

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

Convert Q84.4 to ICD-9-CMHistory

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

ICD-9-CM
757.5 Nail anomalies NEC
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 Q84.4Overview

Is Q84.4 (Other congenital malformations of integument) a billable code?

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

What MS-DRG does Q84.4 group to?

When congenital leukonychia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q84.4 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 congenital leukonychia on inpatient claims.

What is the ICD-9 equivalent of Q84.4?

Under the General Equivalence Mappings, congenital leukonychia converts to ICD-9-CM 757.5 (nail anomalies NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.