O22.31 Deep phlebothrombosis in pregnancy, first trimester

The ICD-10-CM code for Deep phlebothrombosis in pregnancy, first trimester is O22.31 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

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

Section

O20-O29: Other maternal disorders predominantly related to pregnancy (O20-O29)

Category O22

42 codes (32 billable)

FY2026 Status

Stable since FY2024

U.S. Hospital Utilization

• An estimated 575 U.S. inpatient stays in 2023 included O22.31 among the documented diagnoses.
• 280 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.

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)