O10.919 — Unspecified pre-existing hypertension complicating pregnancy, unspecified trimester

O10.919

ICD-10 Chapter 15: Pregnancy, Childbirth & Puerperium — illustrative image — Chapter 15: Pregnancy, childbirth and the puerperium (O00–O9A) — illustrative image

What this code means

Pre-existing hypertension (high blood pressure present before pregnancy) complicating pregnancy; trimester not specified.

Also called: pre-existing hypertension in pregnancy, chronic hypertension pregnancy.

When this code is used

Used for unspecified pre-existing hypertension complicating pregnancy, unspecified trimester.

Where it sits in ICD-10-CM

Code O10.919 belongs to Chapter 15: Pregnancy, childbirth and the puerperium, which covers codes O00–O9A in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Learn more about this condition

Condition guide: Hypertension

Frequently asked questions

What is ICD-10-CM code O10.919?

O10.919 is the ICD-10-CM diagnosis code for “Unspecified pre-existing hypertension complicating pregnancy, unspecified trimester”. Pre-existing hypertension (high blood pressure present before pregnancy) complicating pregnancy; trimester not specified.

When is code O10.919 used?

Used for unspecified pre-existing hypertension complicating pregnancy, unspecified trimester. It belongs to Chapter 15 of ICD-10-CM (Pregnancy, childbirth and the puerperium).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.