2026 ICD-10-CM Diagnosis Code Q84.6Other congenital malformations of nails

ICD-10-CM Codes›Q00-Q99›Q80-Q89›Q84

ICD-10-CM Q84.6
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q84.6 is a billable ICD-10-CM diagnosis code for other congenital malformations of nails. 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
Q84.6
Billable Status
Yes — Valid for Submission
Code Describes
Other congenital malformations of nails
Short Description
Other congenital malformations of nails
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 CodeQ84.6Other congenital malformations of nails

Present on Admission (POA)Billing

Q84.6 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.

  • Abnormally short little finger
  • Agenesis of lunula
  • Alopecia, nail dystrophy, ophthalmic complications, thyroid dysfunction, hypohidrosis, ephelides, enteropathy and respiratory tract infections
  • Anonychia
  • Aplasia of nail unit
  • Autosomal dominant deafness with onychodystrophy syndrome
  • Bifid digit
  • Bifid nail
  • Brachyonychia
  • Clubbing of nail
  • Congenital abnormal shape of rib
  • Congenital anomaly of nail
  • Congenital clubnail
  • Congenital dilatation of colon
  • Congenital dysplasia of nail unit
  • Congenital dysplasia of nail unit of finger
  • Congenital dysplasia of nail unit of toe
  • Congenital hypoplasia of little finger
  • Congenital hypoplasia of nail unit
  • Congenital hypoplasia of nail unit of fifth toe
  • Congenital hypoplasia of nail unit of little finger
  • Congenital hypoplasia of nail unit of thumb
  • Congenital hypoplasia of toenail
  • Congenital isolated onychodysplasia
  • Congenital koilonychia
  • Congenital malalignment of great toenail
  • Congenital malalignment of multiple toenails
  • Congenital onychoatrophy
  • Congenital onychodysplasia of index fingers
  • Congenital osteodystrophy
  • Congenital pectus excavatum
  • Congenital pterygium of nail
  • Curly hair, ankyloblepharon, nail dysplasia syndrome
  • Deafness with onychodystrophy syndrome
  • Deafness, enamel hypoplasia, nail defect syndrome
  • Deformity of sternum
  • Dermotrichic syndrome
  • DOORS syndrome
  • Ectodermal dysplasia with nail defect
  • Hereditary racquet nails
  • Hirschsprung disease with nail hypoplasia and dysmorphism
  • Hypodontia and nail dysgenesis
  • Hypoplasia of distal phalanx of foot
  • Inherited deformity of nail
  • Koilonychia
  • Macronychia
  • Malalignment of nail
  • Mammary digital nail syndrome
  • Melanin pigmentation of oral mucosa
  • Melanosis of mucosa of body orifice
  • Nail and tooth abnormalities, marginal palmoplantar keratoderma, oral hyperpigmentation syndrome
  • Onychoatrophy
  • Onycho-tricho-dysplasia neutropenia syndrome
  • Oto-onycho-peroneal syndrome
  • Pachydermoperiostosis of nail
  • Pectus deformity of chest
  • Pectus excavatum
  • Pectus excavatum, macrocephaly, dysplastic nails syndrome
  • Pili torti onychodysplasia syndrome
  • Polyonychia
  • Pterygium of nail
  • Severe T-cell immunodeficiency, congenital alopecia, nail dystrophy syndrome
  • Shape of nail - finding
  • Trichothiodystrophy

Tabular List NotesGuidance

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

Inclusion Terms

  • Congenital clubnail
  • Congenital koilonychia
  • Congenital malformation of nail NOS

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.

    • Anomaly, anomalous(congenital) (unspecified type)
      • nail
    • Atrophia
      • unguium
        • congenita
    • Brittle
      • nails
        • congenital
    • Clubnail
      • congenital
    • Deformity
      • nail (acquired)
        • congenital
    • Displacement, displaced
      • nail (congenital)
    • Dystrophy, dystrophia
      • nail
        • congenital
    • Dystrophy, dystrophia
      • unguium
        • congenital
    • Egg shell nails
      • congenital
    • Eponychia
    • Fragilitas
      • unguium
        • congenital
    • Furrowed
      • nail (s) (transverse)
        • congenital
    • Horn
      • nail
        • congenital
    • Hypoplasia, hypoplastic
      • nail (s)
    • Koilonychia
      • congenital
    • Longitudinal stripes or grooves, nails
      • congenital
    • Malformation(congenital)
      • nail
    • Malposition
      • congenital
        • nail (s)
    • Onychodystrophy
      • congenital
    • Onychorrhexis
      • congenital
    • Persistence, persistent(congenital)
      • nail (s), anomalous
    • Platyonychia(congenital)
    • Polyunguia
    • Remnant
      • fingernail
        • congenital
    • Spading nail
      • congenital
    • Spoon nail
      • 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

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 Q84.6 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 Q84.6Overview

Is Q84.6 (Other congenital malformations of integument) a billable code?

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

What MS-DRG does Q84.6 group to?

When other congenital malformations of nails 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 Q84.6 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 other congenital malformations of nails on inpatient claims.

What is the ICD-9 equivalent of Q84.6?

Under the General Equivalence Mappings, other congenital malformations of nails 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.