Q84.6 Other congenital malformations of nails

The ICD-10-CM code for Other congenital malformations of nails is Q84.6 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

17: Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)

Section

Q80-Q89: Other congenital malformations (Q80-Q89)

Category Q84

10 codes (9 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to Q84.6:

• Polyunguia
• Eponychia
• Platyonychia (congenital)
• Displacement, displaced › nail (congenital)
• Longitudinal stripes or grooves, nails › congenital
• Egg shell nails › congenital
• Anomaly, anomalous (congenital) (unspecified type) › nail
• Clubnail › congenital

Inclusion Terms

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

U.S. Hospital Utilization

• An estimated 205 U.S. inpatient stays in 2023 included Q84.6 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

POA indicator for congenital conditions/anomalies and Q00-Q99 exception

Congenital conditions and anomalies Assign “Y” for congenital conditions and anomalies except for categories Q00- Q99, Congenital anomalies, which are on the exempt list. Congenital conditions are always considered present on admission.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)