Q85.8 Other phakomatoses, not elsewhere classified

The ICD-10-CM code for Other phakomatoses, not elsewhere classified is Q85.8 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

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

Section

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

Category Q85

14 codes (11 billable)

FY2026 Status

Stable since FY2024

U.S. Hospital Utilization

• An estimated 2,105 U.S. inpatient stays in 2022 included Q85.8 among the documented diagnoses.
• 235 stays listed it as the principal diagnosis.

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)