O02.81 Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy

The ICD-10-CM code for Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy is O02.81 (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 O02

7 codes (5 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to O02.81:

• Inappropriate › level of quantitative human chorionic gonadotropin (hCG) for gestational age in early pregnancy
• Pregnancy (single) (uterine) › chemical
• Pregnancy (single) (uterine) › biochemical
• Inappropriate › change in quantitative human chorionic gonadotropin (hCG) in early pregnancy

Inclusion Terms

• Biochemical pregnancy
• Chemical pregnancy
• Inappropriate level of quantitative human chorionic gonadotropin (hCG) for gestational age in early pregnancy

U.S. Hospital Utilization

• An estimated 90 U.S. inpatient stays in 2023 included O02.81 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

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)