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ICD-10-CM 2027 diagnosis code

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

✓ Billable / specificMCC — major complication/comorbidityMaternity · age 9–64Female only

O11.2 is a valid, billable ICD-10-CM code for pre-existing hypertension with pre-eclampsia, second trimester. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Pre-existing hypertension w pre-eclampsia, second trimester

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O11.2

O11.2 is the ICD-10-CM diagnosis code for pre-existing hypertension with pre-eclampsia, second trimester. It belongs to category O11 (pre-existing hypertension with pre-eclampsia), block O10-O16 (edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium) and chapter 15 (pregnancy, childbirth and the puerperium). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within O11 (pre-existing hypertension with pre-eclampsia), O11.2 is specifically for pre-existing hypertension with pre-eclampsia, second trimester. Related codes cover first trimester (O11.1), third trimester (O11.3), complicating childbirth (O11.4), complicating the puerperium (O11.5) and unspecified trimester (O11.9).

Use an additional code from O10 to identify the type of hypertension.

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 817 (Other Antepartum Diagnoses with O.R. Procedures with MCC, relative weight 2.0534), DRG 818 (Other Antepartum Diagnoses with O.R. Procedures with CC, relative weight 1.2942), DRG 819 (Other Antepartum Diagnoses with O.R. Procedures without CC/MCC, relative weight 0.7739), DRG 831 (Other Antepartum Diagnoses without O.R. Procedures with MCC, relative weight 1.1558), DRG 832 (Other Antepartum Diagnoses without O.R. Procedures with CC, relative weight 0.7585) and DRG 833 (Other Antepartum Diagnoses without O.R. Procedures without CC/MCC, relative weight 0.5002), in MDC 14 (Pregnancy, Childbirth and the Puerperium), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

The Medicare Code Editor treats this as a maternity diagnosis, expected only for patients age 9 through 64.

It is on the CMS list of diagnoses consistent only with female patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 642.21 (other pre-existing hypertension, complicating pregnancy, childbirth, and the puerperium, delivered, with or without mention of antepartum condition), 642.23 (other pre-existing hypertension, complicating pregnancy, childbirth, and the puerperium, antepartum condition or complication), 642.71 (pre-eclampsia or eclampsia superimposed on pre-existing hypertension, delivered, with or without mention of antepartum condition) and 1 more.

Notes that apply from higher levels

Instructions written at a parent level also apply to O11.2.

› From O11 Pre-existing hypertension with pre-eclampsia
Includes
  • conditions in O10 complicated by pre-eclampsia
  • pre-eclampsia superimposed pre-existing hypertension
Use additional code
  • code from O10 to identify the type of hypertension

Broader instructions also apply from Chapter 15: Pregnancy, childbirth and the puerperium.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 642.21Other pre-existing hypertension, complicating pregnancy, childbirth, and the puerperium, delivered, with or without mention of antepartum conditionapproximate
  • 642.23Other pre-existing hypertension, complicating pregnancy, childbirth, and the puerperium, antepartum condition or complicationapproximate
  • 642.71Pre-eclampsia or eclampsia superimposed on pre-existing hypertension, delivered, with or without mention of antepartum conditionapproximate
  • 642.73Pre-eclampsia or eclampsia superimposed on pre-existing hypertension, antepartum condition or complicationapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about O11.2

Is O11.2 billable?

Yes. O11.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can O11.2 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict O11.2 as a principal diagnosis.

Is O11.2 a CC or MCC?

O11.2 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does O11.2 group to?

O11.2 is used in the MS-DRG v44.0 logic for MS-DRG 817 (Other Antepartum Diagnoses with O.R. Procedures with MCC), MS-DRG 818 (Other Antepartum Diagnoses with O.R. Procedures with CC), MS-DRG 819 (Other Antepartum Diagnoses with O.R. Procedures without CC/MCC), MS-DRG 831 (Other Antepartum Diagnoses without O.R. Procedures with MCC), MS-DRG 832 (Other Antepartum Diagnoses without O.R. Procedures with CC) and MS-DRG 833 (Other Antepartum Diagnoses without O.R. Procedures without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for O11.2?

The CMS General Equivalence Mappings map O11.2 to ICD-9-CM 642.21, 642.23, 642.71 and 642.73.