Pre-existing hypertension with pre-eclampsia (O11) ICD-10-CM
The O11 code range covers pre-existing hypertension with pre-eclampsia with 7 ICD-10-CM diagnosis codes. 6 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- conditions in O10
- pre-eclampsia superimposed pre-existing hypertension
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
- code from O10
Codes in the O11 Range 7 codes · 6 billable
- O11 Pre-existing hypertension with pre-eclampsiaNon-billable
- O11.1 Pre-existing hypertension with pre-eclampsia, first trimester
- O11.2 Pre-existing hypertension with pre-eclampsia, second trimester
- O11.3 Pre-existing hypertension with pre-eclampsia, third trimester
- O11.4 Pre-existing hypertension with pre-eclampsia, complicating childbirth
- O11.5 Pre-existing hypertension with pre-eclampsia, complicating the puerperium
- O11.9 Pre-existing hypertension with pre-eclampsia, unspecified trimester
About the O11 Code Range
The ICD-10 code O11 identifies cases of pre-existing hypertension with pre-eclampsia, a condition where chronic high blood pressure in pregnant women is complicated by pre-eclampsia. This code and its subcodes specify the timing of the condition throughout pregnancy, childbirth, and the postpartum period.
These codes are used specifically to document hypertension that existed before pregnancy but becomes complicated by pre-eclampsia, which is a serious disorder characterized by high blood pressure and signs of organ damage during pregnancy. The subcategories—from O11.1 to O11.5—detail whether the condition occurs during the first, second, or third trimester, complicates delivery, or the puerperium (postpartum period). The O11.9 code is used when the trimester is unspecified. This coding section helps healthcare professionals and coders accurately capture the complexity of managing high blood pressure that predated pregnancy and worsens with pre-eclampsia. Though no synonyms are listed for most codes, the O11.9 includes terms like “pre-eclampsia or eclampsia with pre-existing hypertension,” alerting coders that these codes specifically address cases where chronic hypertension is compounded by pregnancy-related hypertensive disorders.
Questions About This Page
How many billable codes are in the O11 range?
Of the 7 codes in this range, 6 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the O11 range classify?
The range classifies pre-existing hypertension with pre-eclampsia. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
