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O24.0 ICD-10-CM Code: Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium

Compare with another code for O24.0Check this code on a claim

Billing Status: NO. This is a non-billable ICD-10-CM code: report a more specific billable code beneath it.

Coding at a Glance

Tabular directives
2 inclusion terms · 2 Excludes2 · 1 use-additional code

Not billable · FY2027A non-billable heading in the tabular list: report a more specific code beneath it.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too, and is marked with where it comes from.

Use additional codeReport with this code when documented
  • Use additional code from category E10 to further identify any manifestations
Excludes2from O20-O29Not included here; may be reported together
  • maternal care related to the fetus and amniotic cavity and possible delivery problems (O30-O48)
  • maternal diseases classifiable elsewhere but complicating pregnancy, labor and delivery, and the puerperium (O98-O99)
IncludesWhat this code covers
  • Juvenile onset diabetes mellitus, in pregnancy, childbirth and the puerperium
  • Ketosis-prone diabetes mellitus in pregnancy, childbirth and the puerperium

Where it sits Source: CMS/NCHS

Under:Chapter 15: Pregnancy, Childbirth and the PuerperiumO20-O29 Other maternal disorders predominantly related to pregnancyO24 Diabetes mellitus in pregnancy, childbirth, and the puerperium

Codes under O24.0 (3)

  • O24.01Pre-existing type 1 diabetes mellitus, in pregnancyNot billable
  • O24.02Pre-existing type 1 diabetes mellitus, in childbirthBillable
  • O24.03Pre-existing type 1 diabetes mellitus, in the puerperiumBillable

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for O24.0 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on O24.0 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Juvenile onset diabetes mellitus, in pregnancy, childbirth and the puerperium
  • Ketosis-prone diabetes mellitus in 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.

Source: inherited from O20-O29

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code from category E10 to further identify any manifestations

Coder workflow for O24.0

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

Before you code O24.0

  1. O24.0 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).

    ReviewO24.01, O24.02, O24.03

    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 O24.0?
    Yes → Select that code and continue the checks below on its own page.
    No → O24.0 cannot be reported as written. Where the codes beneath it include an unspecified code, that code applies when the record goes no further; otherwise query for the missing detail.

    ReviewO24.01, O24.02, O24.03

Report the code beneath O24.0 that the documentation supports, not O24.0 itself. Then work the Use Additional Code note, and confirm that code is valid for the date of service on its own page.

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).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes2 — not part of O24.0(2 notes)

    Coding workflow: The conditions named in this note are not included in O24.0. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

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

  • Use Additional Code — after identifying O24.0(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with O24.0 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewE10

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with the code beneath O24.0?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewE10

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.

Don’t confuse O24.0 with…

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

The codes most likely to be picked instead of O24.0 — 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.

  • O24.3— 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 “Unspecified pre-existing diabetes mellitus in pregnancy, childbirth and the puerperium” takes O24.3; specificity in the record moves it back here.

    Full comparison: O24.0 vs O24.3 →

  • O30— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal care related to the fetus and amniotic cavity and possible delivery problems adds O30; it is not part of this code and both may be reported when both are documented.

    Full comparison: O24.0 vs O30 →

  • O48— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal care related to the fetus and amniotic cavity and possible delivery problems adds O48; it is not part of this code and both may be reported when both are documented.

    Full comparison: O24.0 vs O48 →

  • O98— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal diseases classifiable elsewhere but complicating pregnancy, labor and delivery, and the puerperium adds O98; it is not part of this code and both may be reported when both are documented.

    Full comparison: O24.0 vs O98 →

  • O99— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of maternal diseases classifiable elsewhere but complicating pregnancy, labor and delivery, and the puerperium adds O99; it is not part of this code and both may be reported when both are documented.

    Full comparison: O24.0 vs O99 →

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.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium is a non-billable ICD-10-CM category code (O24.0). 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.

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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name O24.0 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: R73 — Elevated blood glucose level (via O24.-).

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

Referenced by 1 Excludes2 note: O99.2 — Endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperium (via O24.-).

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

Contextual Map

Every relationship of O24.0 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 O24.0 with these 2 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • R73 — Elevated blood glucose level[Excludes1](via O24.-): “diabetes mellitus in pregnancy, childbirth and the puerperium (O24.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Referenced by Excludes2 notes

Nearest codes (40)

Change history (3)

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Common coding questions

MedCoder editorial

Can O24.0 be billed directly?

No. O24.0 (Pre-existing type 1 diabetes mellitus, in 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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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-derived 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 editorial 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

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. "O24.0 — Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/o24.0-pre-existing-type-1-diabetes-mellitus-in-pregnancy-childbirth-and-the-puerperium

Change history

  • FY2017 — October 1, 2016
    Description revised
    Pre-existing diabetes mellitus, type 1, in pregnancy, childbirth and the puerperium → Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium
    FY2017 changes
  • FY2017 — October 1, 2016
    Short description revised
    Pre-exist diabetes, type 1, in preg, chldbrth and the puerp → Pre-exist type 1 diabetes, in preg, chldbrth and the puerp
    FY2017 changes
  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Pre-existing diabetes mellitus, type 1, in pregnancy, childbirth and the puerperium

Nearest Codes in This Family

Official ICD-10-CM classifications closest to O24.0 in its code family, with their registry titles.

View all codes in the O24 family