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

Q84.4 is a billable ICD-10-CM diagnosis code for congenital leukonychia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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 the other POA exempt codes in Other congenital malformations (Q80-Q89).

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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q84.4: its own notes plus those printed at Chapter 17. A note printed at a category, block or chapter applies to every code under it.

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 Q84.4, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming Q84.4: they are not reported together with it, unless the two conditions are unrelated.

  • Block L60-L75 Disorders of skin appendages
    congenital malformations of integument (Q84.-) names Q84.-, which includes this code
  • P83 Other conditions of integument specific to newborn
    congenital malformations of skin and integument (Q80-Q84) names Q80-Q84, 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 MAL010
Other specified and unspecified congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

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

Questions About Q84.4Overview

What is the ICD-10 code for congenital leukonychia?

The ICD-10-CM code for congenital leukonychia is Q84.4 (sometimes written as Q844). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does Q84.4 group to?

When congenital leukonychia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 607, 606, with relative weights from 0.8772 to 1.5721 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. The code appears in the Other congenital malformations (Q80-Q89) range of the CMS exempt list.

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.