O01.9 Hydatidiform mole, unspecified

The ICD-10-CM code for Hydatidiform mole, unspecified is O01.9 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

15: Pregnancy, childbirth and the puerperium (O00-O9A)

Section

O00-O08: Pregnancy with abortive outcome (O00-O08)

Category O01

4 codes (3 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to O01.9:

• Trophoblastic disease
• Hydatidiform mole (benign) (complicating pregnancy) (delivered) (undelivered)
• Mole (pigmented) › hydatid, hydatidiform (benign) (complicating pregnancy) (delivered) (undelivered)
• Pregnancy (single) (uterine) › molar NEC › hydatidiform
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › hydatidiform mole

Inclusion Terms

• Trophoblastic disease NOS
• Vesicular mole NOS

U.S. Hospital Utilization

• An estimated 150 U.S. inpatient stays in 2023 included O01.9 among the documented diagnoses.
• 60 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

Z3A—do not assign for O00-O08, Z33.2, or postpartum conditions

Category Z3A codes should not be assigned for pregnancies with abortive outcomes (categories O00- O08), elective termination of pregnancy (code Z33.2), nor for postpartum conditions, as category Z3A is not applicable to these conditions.

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)