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O31.30X4 ICD-10-CM Code: Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 4

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
3 Excludes2

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 817 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH MCC (MDC 14)
  • MS-DRG 818 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH CC (MDC 14)
  • MS-DRG 819 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)
  • MS-DRG 831 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH MCC (MDC 14)
  • MS-DRG 832 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH CC (MDC 14)
  • MS-DRG 833 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for O31.30X4 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on O31.30X4 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

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

Source: inherited from O31

7th Character Guide

"One of the following 7th characters is to be assigned to each code under category O31. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30, Multiple gestation, must also be assigned when assigning a code from category O31 that has a 7th character of 1 through 9."

  • 0 — not applicable or unspecified
  • 1 — fetus 1
  • 2 — fetus 2
  • 3 — fetus 3
  • 4 — fetus 4 (this page’s code)
  • 5 — fetus 5
  • 9 — other fetus

Variant codes in this family

O31.30X0, O31.30X1, O31.30X2, O31.30X3, O31.30X4, O31.30X5, O31.30X9

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for O31.30X4

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

Before you code O31.30X4

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, O31.30X4 may be the appropriate code. Check the record for detail that supports a more specific sibling — in this subcategory the siblings differ by trimester, the fetus affected. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. A 7th character is required in this family. Confirm the documentation supports the character assigned — its meaning in this family is defined in the official instruction. This page’s code carries “4”. The official 7th-character definitions for this family are quoted in the guide.

    See the 7th Character Guide

  3. 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 record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — O31.30X4 is appropriate when the documentation goes no further.
  2. Does the documentation support one of this family’s 7th-character values?
    Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
    No → The code is invalid without its 7th character — query for the missing element.

Consider O31.30X4. 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).
7th-character basis
The documented element this family’s 7th character records (see the official definitions in the 7th Character Guide).
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).
Fetus affected
For multiple gestations, the fetus the condition affects, as documented.
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes2 — not part of O31.30X4(3 notes)

    Coding workflow: The conditions named in this note are not included in O31.30X4. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareO63.2, O32.9, O43.0

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

Coding decision scenarios

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

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the subcategory for a sibling that names the missing detail.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

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

Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 4 is a billable ICD-10-CM diagnosis code (O31.30X4).

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)

6) 7th character for fetus identification Where applicable, a 7th character is to be assigned for certain categories (O31, O32, O33.3 - O33.6, O35, O36, O40, O41, O60.1, O60.2, O64, and O69) to identify the fetus for which the complication code applies.

Verify Before Coding

  • Age-restricted: the Medicare Code Editor lists this as a maternity (age 9-64) diagnosis; other ages are presumed incorrect.

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 O31.30X4 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 8 Excludes1 notes: O00 — Ectopic pregnancy (via O31.3.-), O00-O08 — Pregnancy with abortive outcome (O00-O08) (via O31.3.-), O01 — Hydatidiform mole (via O31.3.-), O02 — Other abnormal products of conception (via O31.3.-), O03 — Spontaneous abortion (via O31.3.-), O04 — Complications following (induced) termination of pregnancy (via O31.3.-), O07 — Failed attempted termination of pregnancy (via O31.3.-), O08 — Complications following ectopic and molar pregnancy (via O31.3.-).

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

Referenced by 10 Excludes2 notes: O20 — Hemorrhage in early pregnancy (via O31.-), O20-O29 — Other maternal disorders predominantly related to pregnancy (O20-O29) (via O31.-), O21 — Excessive vomiting in pregnancy (via O31.-), O22 — Venous complications and hemorrhoids in pregnancy (via O31.-), O23 — Infections of genitourinary tract in pregnancy (via O31.-), O24 — Diabetes mellitus in pregnancy, childbirth, and the puerperium (via O31.-), O25 — Malnutrition in pregnancy, childbirth and the puerperium (via O31.-), O26 — Maternal care for other conditions predominantly related to pregnancy (via O31.-), O28 — Abnormal findings on antenatal screening of mother (via O31.-), O29 — Complications of anesthesia during pregnancy (via O31.-).

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

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

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):PRG012 — Multiple gestation (default).

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 category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Multiple gestation).

O31.23X1 — Continuing pregnancy after intrauterine death of one fetus or more, third trimester, fetus 1, O31.23X2 — Continuing pregnancy after intrauterine death of one fetus or more, third trimester, fetus 2, O31.23X3 — Continuing pregnancy after intrauterine death of one fetus or more, third trimester, fetus 3, O31.23X4 — Continuing pregnancy after intrauterine death of one fetus or more, third trimester, fetus 4, O31.23X5 — Continuing pregnancy after intrauterine death of one fetus or more, third trimester, fetus 5, O31.23X9 — Continuing pregnancy after intrauterine death of one fetus or more, third trimester, other fetus, O31.30X0 — Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, not applicable or unspecified, O31.30X1 — Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 1, O31.30X2 — Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 2, O31.30X3 — Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 3, O31.30X5 — Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 5, O31.30X9 — Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, other fetus, O31.31X0 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, not applicable or unspecified, O31.31X1 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 1, O31.31X2 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 2, O31.31X3 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 3, O31.31X4 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 4, O31.31X5 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 5, O31.31X9 — Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, other fetus, O31.32X0 — Continuing pregnancy after elective fetal reduction of one fetus or more, second trimester, not applicable or unspecified, +207 more

Contextual Map

Every relationship of O31.30X4 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 O31.30X4 with these 16 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • O00 — Ectopic pregnancy[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O00-O08 — Pregnancy with abortive outcome (O00-O08)[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O01 — Hydatidiform mole[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O02 — Other abnormal products of conception[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O03 — Spontaneous abortion[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O04 — Complications following (induced) termination of pregnancy[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O07 — Failed attempted termination of pregnancy[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • O08 — Complications following ectopic and molar pregnancy[Excludes1](via O31.3.-): “continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes (10)

Clinical classification (CCSR)

MS-DRG Grouper

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

Nearest codes (40)

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

Does O31.30X4 require a 7th character?

Yes. One of the following 7th characters is to be assigned to each code under category O31. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30, Multiple gestation, must also be assigned when assigning a code from category O31 that has a 7th character of 1 through 9..

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
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

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Continuing pregnancy after elective fetal reduction of one fetus or more, unspecified trimester, fetus 4

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 O31.30X4 in its code family, with their registry titles.

View all codes in the O31 family