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O10 ICD-10-CM Code: Pre-existing hypertension complicating pregnancy, childbirth and the puerperium

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

Tabular directives
1 inclusion term · 1 Excludes2

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for O10 in the official ICD-10-CM tabular list, quoted as published.

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

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • pre-existing hypertension with pre-existing proteinuria complicating pregnancy, childbirth and the puerperium

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • pre-existing hypertension with superimposed pre-eclampsia complicating pregnancy, childbirth and the puerperium (O11.-) Compare O10 vs O11 →

Coder workflow for O10

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

Before you code O10

  1. O10 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewO10.0, O10.1, O10.2, O10.3, O10.4, O10.9

    See the relationships section · Guide: How to choose an ICD-10-CM code →

  2. 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 →

Choose the right path

  1. Does the documentation support one of the more specific codes beneath O10?
    Yes → Select that code and continue the checks below on its own page.
    No → O10 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewO10.0, O10.1, O10.2, O10.3, O10.4, O10.9

Consider O10. Then confirm the code is valid for the date of service in the Verify section.

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).

Official instructions as workflow

  • Excludes2 — not part of O10(1 note)

    Coding workflow: The conditions named in this note are not included in O10. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareO11

    See the official tabular notes · Guidelines I.A.12.b

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.

Code Overview

Pre-existing hypertension complicating pregnancy, childbirth and the puerperium is a non-billable ICD-10-CM category code (O10). A more specific billable subcode must be selected for claims submission.

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 15: Pregnancy, Childbirth, and the Puerperium (O00-O9A)

d. Pre-existing hypertension in pregnancy Category O10, Pre-existing hypertension complicating pregnancy, childbirth and the puerperium, includes codes for hypertensive heart and hypertensive chronic kidney disease. When assigning one of the O10 codes that includes hypertensive heart disease or hypertensive chronic kidney disease, it is necessary to add a secondary code from the appropriate hypertension category to specify the type of heart failure or chronic kidney disease.

Verify Before Coding

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 O10 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.

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), I11 — Hypertensive heart disease, I12 — Hypertensive chronic kidney disease, I13 — Hypertensive heart and chronic kidney disease, I15 — Secondary hypertension, I16 — Hypertensive crisis, I1A — Other hypertension, O99.4 — Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium.

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

Contextual Map

Every relationship of O10 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 O10 with these 10 related codes in Claim Check

Hierarchy

Excludes2

Referenced by Excludes1 notes

  • I10 — Essential (primary) hypertension[Excludes1]: “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

Nearest codes (48)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Can O10 be billed directly?

No. O10 (Pre-existing hypertension complicating pregnancy, childbirth and the puerperium) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

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
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section 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
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

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "O10 — Pre-existing hypertension complicating pregnancy, childbirth and the puerperium." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/o10-pre-existing-hypertension-complicating-pregnancy-childbirth-and-the-puerperium

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Pre-existing hypertension complicating pregnancy, childbirth and the puerperium

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to O10 in its code family, with their registry titles.