2027 ICD-10-CM Diagnosis Code O11Pre-existing hypertension with pre-eclampsia

ICD-10-CM Codes›O00-O9A›O10-O16›O11

ICD-10-CM O11
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O11 is a non-billable ICD-10-CM category code for pre-existing hypertension with pre-eclampsia, so it cannot be submitted on claims. Use a more specific code from this category instead, such as O11.1, O11.2, O11.3, and O11.4.

Code Identity

ICD-10-CM Code
O11
Billable Status
No — Non-Billable Category
Code Describes
Pre-existing hypertension with pre-eclampsia
Short Description
Pre-existing hypertension with pre-eclampsia
Same as the full description in the CMS dataset.
Chapter
O10-O16
Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO10-O16Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium
CategoryO11Pre-existing hypertension with pre-eclampsia
This CodeO11Pre-existing hypertension with pre-eclampsia

Specific Coding for Pre-existing hypertension with pre-eclampsiaOverview

Non-specific codes like O11 require more characters. Use one of these billable codes instead:

  • Use O11.1 for Pre-existing hypertension with pre-eclampsia, first trimester

  • Use O11.2 for Pre-existing hypertension with pre-eclampsia, second trimester

  • Use O11.3 for Pre-existing hypertension with pre-eclampsia, third trimester

  • Use O11.4 for Pre-existing hypertension with pre-eclampsia, complicating childbirth

  • Use O11.5 for Pre-existing hypertension with pre-eclampsia, complicating the puerperium

  • Use O11.9 for Pre-existing hypertension with pre-eclampsia, unspecified trimester

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O11: its own notes plus those printed at Chapter 15. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

  • conditions in O10 complicated by pre-eclampsia
  • pre-eclampsia superimposed pre-existing hypertension

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • supervision of normal pregnancy (Z34.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

On O11 itself
  • code from O10 to identify the type of hypertension
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Notes

General instructions on how these codes are used.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
  • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
  • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
  • 1st trimester- less than 14 weeks 0 days
  • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
  • 3rd trimester- 28 weeks 0 days until delivery

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O11, its category, or a range that includes it.

Includes 1

These notes mention O11.

  • O15 Eclampsia
    convulsions following conditions in O10-O14 and O16 names O10-O14, which includes this code

Applicable To 1

These notes mention O11.

  • P00.0 Newborn affected by maternal hypertensive disorders
    Newborn affected by maternal conditions classifiable to O10-O11, O13-O16 names O10-O11, which includes this code

Excludes1 2

These codes carry an Excludes1 note naming O11: they are not reported together with it, unless the two conditions are unrelated.

  • O14 Pre-eclampsia
    pre-existing hypertension with pre-eclampsia (O11)
  • I10 Essential (primary) hypertension
    hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16) names O10-O11, which includes this code

Excludes2 3

These codes carry an Excludes2 note naming O11: its condition is not part of those codes, and both may be reported when the patient has both.

  • O10 Pre-existing hypertension complicating pregnancy, childbirth and the puerperium
    pre-existing hypertension with superimposed pre-eclampsia complicating pregnancy, childbirth and the puerperium (O11.-)
  • Block I10-I1A Hypertensive diseases
    hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16) names O10-O11, which includes this code
  • O99.4 Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium
    hypertensive disorders (O10-O16) names O10-O16, which includes this code

Patient EducationClinical

High Blood Pressure in Pregnancy

Blood pressure is the force of your blood pushing against the walls of your arteries. Your arteries are blood vessels that carry blood from your heart to other parts of your body. High blood pressure, or hypertension, is blood pressure that is higher than normal.

The full article covers:

  • What is high blood pressure in pregnancy?
  • What are the types of high blood pressure in pregnancy?
  • Who is more likely to develop high blood pressure in pregnancy?
  • What are the symptoms of high blood pressure in pregnancy?
  • What problems can high blood pressure in pregnancy cause?
  • How is high blood pressure in pregnancy diagnosed?
  • What are the treatments for high blood pressure in pregnancy?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About O11Overview

What is the ICD-10 code for pre-existing hypertension with pre-eclampsia?

O11 is the ICD-10-CM category for pre-existing hypertension with pre-eclampsia, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is O11 (Pre-existing hypertension with pre-eclampsia) a billable code?

No. This is a category header that groups the codes for pre-existing hypertension with pre-eclampsia, and headers cannot be submitted on claims. Claims for pre-existing hypertension with pre-eclampsia need a more specific code from this category, such as O11.1, O11.2, and O11.3.

Does O11 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code from O10 to identify the type of hypertension. The additional code is reported after O11.