O15.1 ICD-10-CM Code: Eclampsia complicating labor

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for O15.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on O15.1 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for O15.1

MedCoder structured workflow — derived from this code’s own official record

Before you code O15.1

1. Confirm the condition is documented as complicating the pregnancy, childbirth, or the puerperium, and check the trimester where the code carries one and the fetus character where the category requires it. Chapter 15 codes belong on the maternal record only and take sequencing priority over codes from other chapters. It is the provider’s responsibility to state that a condition is not affecting the pregnancy; the trimester is assigned from the documentation (Guidelines I.C.15.a, I.C.15.a.1, I.C.15.a.3).

   Guide: How to choose an ICD-10-CM code →

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Trimester

Assigned from the documented trimester at the encounter, or the trimester in which the condition developed for inpatient stays (Guidelines I.C.15.a.3).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Delivery (childbirth) (labor), complicated, by, eclampsia
• Eclampsia, eclamptic NEC (coma) (convulsions) (delirium) (with hypertension), complicating, labor and delivery

Don’t confuse O15.1 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of O15.1 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• O15.9— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Eclampsia, unspecified as to time period” takes O15.9; specificity in the record moves it back here.

  Full comparison: O15.1 vs O15.9 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• Age-restricted: the Medicare Code Editor lists this as a maternity (age 9-64) diagnosis; other ages are presumed incorrect.
• MCC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name O15.1 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: I10 — Essential (primary) hypertension (via O15.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 8 Excludes2 notes across 2 chapters: I10-I1A — Hypertensive diseases (I10-I1A) (via O15.-), I11 — Hypertensive heart disease (via O15.-), I12 — Hypertensive chronic kidney disease (via O15.-), I13 — Hypertensive heart and chronic kidney disease (via O15.-), I15 — Secondary hypertension (via O15.-), I16 — Hypertensive crisis (via O15.-), I1A — Other hypertension (via O15.-), O99.4 — Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium (via O15.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 1 Code First instruction: I67.841 — Reversible cerebrovascular vasoconstriction syndrome.

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 1 Code Also instruction: I16.1 — Hypertensive emergency (via O15.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 298 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 6 MS-DRGs: DRG 817 (MDC 14), DRG 818 (MDC 14), DRG 819 (MDC 14), DRG 831 (MDC 14), DRG 832 (MDC 14), DRG 833 (MDC 14).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):PRG020 — Hypertension and hypertensive-related conditions complicating pregnancy; childbirth; and the puerperium (default); PRG023 — Complications specified during childbirth.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

O14.24 — HELLP syndrome, complicating childbirth, O14.25 — HELLP syndrome, complicating the puerperium, O14.90 — Unspecified pre-eclampsia, unspecified trimester, O14.92 — Unspecified pre-eclampsia, second trimester, O14.93 — Unspecified pre-eclampsia, third trimester, O14.94 — Unspecified pre-eclampsia, complicating childbirth, O14.95 — Unspecified pre-eclampsia, complicating the puerperium, O15.00 — Eclampsia complicating pregnancy, unspecified trimester, O15.02 — Eclampsia complicating pregnancy, second trimester, O15.03 — Eclampsia complicating pregnancy, third trimester, O15.2 — Eclampsia complicating the puerperium, O15.9 — Eclampsia, unspecified as to time period, O16.1 — Unspecified maternal hypertension, first trimester, O16.2 — Unspecified maternal hypertension, second trimester, O16.3 — Unspecified maternal hypertension, third trimester, O16.4 — Unspecified maternal hypertension, complicating childbirth, O16.5 — Unspecified maternal hypertension, complicating the puerperium, O16.9 — Unspecified maternal hypertension, unspecified trimester, O25.10 — Malnutrition in pregnancy, unspecified trimester, O25.11 — Malnutrition in pregnancy, first trimester, +277 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Hypertension and hypertensive-related conditions complicating pregnancy; childbirth; and the puerperium, Complications specified during childbirth).

O14.24 — HELLP syndrome, complicating childbirth, O14.25 — HELLP syndrome, complicating the puerperium, O14.90 — Unspecified pre-eclampsia, unspecified trimester, O14.92 — Unspecified pre-eclampsia, second trimester, O14.93 — Unspecified pre-eclampsia, third trimester, O14.94 — Unspecified pre-eclampsia, complicating childbirth, O14.95 — Unspecified pre-eclampsia, complicating the puerperium, O15.00 — Eclampsia complicating pregnancy, unspecified trimester, O15.02 — Eclampsia complicating pregnancy, second trimester, O15.03 — Eclampsia complicating pregnancy, third trimester, O15.2 — Eclampsia complicating the puerperium, O15.9 — Eclampsia, unspecified as to time period, O16.1 — Unspecified maternal hypertension, first trimester, O16.2 — Unspecified maternal hypertension, second trimester, O16.3 — Unspecified maternal hypertension, third trimester, O16.4 — Unspecified maternal hypertension, complicating childbirth, O16.5 — Unspecified maternal hypertension, complicating the puerperium, O16.9 — Unspecified maternal hypertension, unspecified trimester, O24.02 — Pre-existing type 1 diabetes mellitus, in childbirth, O24.12 — Pre-existing type 2 diabetes mellitus, in childbirth, +157 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Delivery”; these codes share that main term but sit in a different category of the Tabular List.

O02.1 — Missed abortion (complicated, by, fetal, death, early), O12.04 — Gestational edema, complicating childbirth (complicated, by, gestational, edema), O12.14 — Gestational proteinuria, complicating childbirth (complicated, by, gestational, proteinuria), O12.24 — Gestational edema with proteinuria, complicating childbirth (complicated, by, gestational, edema, with proteinuria), O14.04 — Mild to moderate pre-eclampsia, complicating childbirth (cesarean, pre-eclampsia, mild), O14.14 — Severe pre-eclampsia complicating childbirth (cesarean, pre-eclampsia, severe), O14.24 — HELLP syndrome, complicating childbirth (cesarean, pre-eclampsia, severe, with hemolysis, elevated liver enzymes and low platelet count), O14.94 — Unspecified pre-eclampsia, complicating childbirth (cesarean, pre-eclampsia), O24.02 — Pre-existing type 1 diabetes mellitus, in childbirth (complicated, by, diabetes, pre-existing, type 1), O24.12 — Pre-existing type 2 diabetes mellitus, in childbirth (complicated, by, diabetes, pre-existing, type 2), O24.32 — Unspecified pre-existing diabetes mellitus in childbirth (complicated, by, diabetes, pre-existing), O24.420 — Gestational diabetes mellitus in childbirth, diet controlled (complicated, by, diabetes, gestational, diet controlled), O24.424 — Gestational diabetes mellitus in childbirth, insulin controlled (complicated, by, gestational, diabetes, insulincontrolled), O24.425 — Gestational diabetes mellitus in childbirth, controlled by oral hypoglycemic drugs (complicated, by, gestational, diabetes, oral drug controlled), O24.429 — Gestational diabetes mellitus in childbirth, unspecified control (complicated, by, gestational, diabetes), O24.82 — Other pre-existing diabetes mellitus in childbirth (complicated, by, diabetes, pre-existing, specified NEC), O24.92 — Unspecified diabetes mellitus in childbirth (complicated, by, diabetes), O25.2 — Malnutrition in childbirth (complicated, by, malnutrition), O26.5 — Maternal hypotension syndrome (complicated, by, hypotension), O26.62 — Liver and biliary tract disorders in childbirth (complicated, by, liver disorder), +177 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Partial Thromboplastin Time (PTT) Test, Pregnancy Test, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of O15.1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run O15.1 with these 11 related codes in Claim Check

Hierarchy

• O00-O9A — Chapter 15: Pregnancy, Childbirth and the Puerperium (O00-O9A) (O00-O9A)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O10-O16 — Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• I10 — Essential (primary) hypertension[Excludes1](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

• I10-I1A — Hypertensive diseases (I10-I1A)[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I11 — Hypertensive heart disease[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I12 — Hypertensive chronic kidney disease[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I13 — Hypertensive heart and chronic kidney disease[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I15 — Secondary hypertension[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I16 — Hypertensive crisis[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I1A — Other hypertension[Excludes2](via O15.-): “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O99.4 — Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium[Excludes2](via O15.-): “hypertensive disorders (O10-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

• I67.841 — Reversible cerebrovascular vasoconstriction syndrome[Code First]: “underlying condition, if applicable, such as eclampsia (O15.00-O15.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code Also instructions

• I16.1 — Hypertensive emergency[Code Also](via O15.-): “eclampsia (O15.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• PRG020 — Hypertension and hypertensive-related conditions complicating pregnancy; childbirth; and the puerperium[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• PRG023 — Complications specified during childbirth[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• MCC — Major Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (MCC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 817 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH MCC[MS-DRG]: “OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH MCC (MDC 14)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 818 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH CC[MS-DRG]: “OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH CC (MDC 14)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 819 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITHOUT CC/MCC[MS-DRG]: “OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 831 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH MCC[MS-DRG]: “OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH MCC (MDC 14)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 832 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH CC[MS-DRG]: “OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH CC (MDC 14)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 833 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITHOUT CC/MCC[MS-DRG]: “OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 14 — Pregnancy, Childbirth and the Puerperium[MDC crossing]: “Pregnancy, Childbirth and the Puerperium — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 94 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Delivery (childbirth) (labor), complicated, by, eclampsia[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Eclampsia, eclamptic NEC (coma) (convulsions) (delirium) (with hypertension), complicating, labor and delivery[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

• O15 — Eclampsia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O15.0 — Eclampsia complicating pregnancy[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O15.00 — Eclampsia complicating pregnancy, unspecified trimester[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O15.02 — Eclampsia complicating pregnancy, second trimester[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O15.03 — Eclampsia complicating pregnancy, third trimester[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O15.2 — Eclampsia complicating the puerperium[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• O15.9 — Eclampsia, unspecified as to time period[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Change history (3)

• FY2017 — Description revised[Change history]— CMS release files (code change ledger) · icd10cm-fy2017
• and 2 more

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Inpatient payment groups Official source data

CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to O15.1 in its code family, with their registry titles.

• O15 — Eclampsia
• O15.0 — Eclampsia complicating pregnancy
• O15.00 — Eclampsia complicating pregnancy, unspecified trimester
• O15.02 — Eclampsia complicating pregnancy, second trimester
• O15.03 — Eclampsia complicating pregnancy, third trimester
• O15.2 — Eclampsia complicating the puerperium
• O15.9 — Eclampsia, unspecified as to time period

View all codes in the O15 family