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O23.33 ICD-10-CM Code: Infections of other parts of urinary tract in pregnancy, third trimester

Compare with another codeCheck this code on a claim

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

Coding at a Glance

Tabular directives
7 Excludes2 · 1 use-additional code

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

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; the Instructions section marks which is which.

Use additional codeReport with this code when documented
  • code to identify organism (B95.-, B96.-)
Excludes2Not included here; may be reported together
  • gonococcal infections complicating pregnancy, childbirth and the puerperium (O98.2)
  • infections with a predominantly sexual mode of transmission NOS complicating pregnancy, childbirth and the puerperium (O98.3)
  • syphilis complicating pregnancy, childbirth and the puerperium (O98.1)
  • tuberculosis of genitourinary system complicating pregnancy, childbirth and the puerperium (O98.0)

+3 more in Instructions

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

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 v44, 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 O23.33 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 O23.33 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.

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify organism (B95.-, B96.-)

Source: inherited from O23

Coder workflow for O23.33

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

Before you code O23.33

  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).
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 O23.33(7 notes)

    Coding workflow: The conditions named in this note are not included in O23.33. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareO98.2, O98.3, O98.1, O98.0

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

  • Use Additional Code — after identifying O23.33(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with O23.33 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewB95, B96

    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 O23.33?

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).

ReviewB95, B96

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 O23.33 with…

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

The codes most likely to be picked instead of O23.33 — 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.

  • O23.30— 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 “Infections of other parts of urinary tract in pregnancy, unspecified trimester” takes O23.30; specificity in the record moves it back here.

    Full comparison: O23.33 vs O23.30 →

  • O98.2— 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 gonococcal infections complicating pregnancy, childbirth and the puerperium adds O98.2; it is not part of this code and both may be reported when both are documented.

    Full comparison: O23.33 vs O98.2 →

  • O98.3— 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 infections with a predominantly sexual mode of transmission NOS complicating pregnancy, childbirth and the puerperium adds O98.3; it is not part of this code and both may be reported when both are documented.

    Full comparison: O23.33 vs O98.3 →

  • O98.1— 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 syphilis complicating pregnancy, childbirth and the puerperium adds O98.1; it is not part of this code and both may be reported when both are documented.

    Full comparison: O23.33 vs O98.1 →

  • O98.0— 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 tuberculosis of genitourinary system complicating pregnancy, childbirth and the puerperium adds O98.0; it is not part of this code and both may be reported when both are documented.

    Full comparison: O23.33 vs O98.0 →

  • 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: O23.33 vs O30 →

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

Infections of other parts of urinary tract in pregnancy, third trimester is a billable ICD-10-CM diagnosis code (O23.33).

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

  • Age-restricted: the Medicare Code Editor lists this as a maternity (age 9-64) diagnosis; other ages are presumed incorrect.
  • CC as a secondary diagnosis (FY2027). 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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name O23.33 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 9 Excludes1 notes: N70 — Salpingitis and oophoritis (via O23.-), N70-N77 — Inflammatory diseases of female pelvic organs (N70-N77) (via O23.-), N71 — Inflammatory disease of uterus, except cervix (via O23.-), N72 — Inflammatory disease of cervix uteri (via O23.-), N73 — Other female pelvic inflammatory diseases (via O23.-), N74 — Female pelvic inflammatory disorders in diseases classified elsewhere (via O23.-), N75 — Diseases of Bartholin's gland (via O23.-), N76 — Other inflammation of vagina and vulva (via O23.-), N77 — Vulvovaginal ulceration and inflammation in diseases classified elsewhere (via O23.-).

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

Referenced by 11 Excludes2 notes across 2 chapters: N30 — Cystitis (via O23.-), N30-N39 — Other diseases of the urinary system (N30-N39) (via O23.-), N31 — Neuromuscular dysfunction of bladder, not elsewhere classified (via O23.-), N32 — Other disorders of bladder (via O23.-), N33 — Bladder disorders in diseases classified elsewhere (via O23.-), N34 — Urethritis and urethral syndrome (via O23.-), N35 — Urethral stricture (via O23.-), N36 — Other disorders of urethra (via O23.-), N37 — Urethral disorders in diseases classified elsewhere (via O23.-), N39 — Other disorders of urinary system (via O23.-), O99.8 — Other specified diseases and conditions complicating pregnancy, childbirth and the puerperium (via O23.-).

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

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: CC — 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 263 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):PRG028 — Other specified complications in pregnancy (default); GEN004 — Urinary tract infections.

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 CC — 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.

O23.11 — Infections of bladder in pregnancy, first trimester, O23.12 — Infections of bladder in pregnancy, second trimester, O23.13 — Infections of bladder in pregnancy, third trimester, O23.20 — Infections of urethra in pregnancy, unspecified trimester, O23.21 — Infections of urethra in pregnancy, first trimester, O23.22 — Infections of urethra in pregnancy, second trimester, O23.23 — Infections of urethra in pregnancy, third trimester, O23.30 — Infections of other parts of urinary tract in pregnancy, unspecified trimester, O23.31 — Infections of other parts of urinary tract in pregnancy, first trimester, O23.32 — Infections of other parts of urinary tract in pregnancy, second trimester, O23.40 — Unspecified infection of urinary tract in pregnancy, unspecified trimester, O23.41 — Unspecified infection of urinary tract in pregnancy, first trimester, O23.42 — Unspecified infection of urinary tract in pregnancy, second trimester, O23.43 — Unspecified infection of urinary tract in pregnancy, third trimester, O23.511 — Infections of cervix in pregnancy, first trimester, O23.512 — Infections of cervix in pregnancy, second trimester, O23.513 — Infections of cervix in pregnancy, third trimester, O23.519 — Infections of cervix in pregnancy, unspecified trimester, O23.521 — Salpingo-oophoritis in pregnancy, first trimester, O23.522 — Salpingo-oophoritis in pregnancy, second trimester, +242 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Other specified complications in pregnancy, Urinary tract infections).

O23.03 — Infections of kidney in pregnancy, third trimester, O23.10 — Infections of bladder in pregnancy, unspecified trimester, O23.11 — Infections of bladder in pregnancy, first trimester, O23.12 — Infections of bladder in pregnancy, second trimester, O23.13 — Infections of bladder in pregnancy, third trimester, O23.20 — Infections of urethra in pregnancy, unspecified trimester, O23.21 — Infections of urethra in pregnancy, first trimester, O23.22 — Infections of urethra in pregnancy, second trimester, O23.23 — Infections of urethra in pregnancy, third trimester, O23.30 — Infections of other parts of urinary tract in pregnancy, unspecified trimester, O23.31 — Infections of other parts of urinary tract in pregnancy, first trimester, O23.32 — Infections of other parts of urinary tract in pregnancy, second trimester, O23.40 — Unspecified infection of urinary tract in pregnancy, unspecified trimester, O23.41 — Unspecified infection of urinary tract in pregnancy, first trimester, O23.42 — Unspecified infection of urinary tract in pregnancy, second trimester, O23.43 — Unspecified infection of urinary tract in pregnancy, third trimester, O86.20 — Urinary tract infection following delivery, unspecified, O86.21 — Infection of kidney following delivery, O86.22 — Infection of bladder following delivery, O86.29 — Other urinary tract infection following delivery, +339 more

Contextual Map

Every relationship of O23.33 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 O23.33 with these 16 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes (9)

Referenced by Excludes2 notes (11)

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 · FY2027

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

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.

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
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 — v44 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. "O23.33 — Infections of other parts of urinary tract in pregnancy, third trimester." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/o23.33-infections-of-other-parts-of-urinary-tract-in-pregnancy-third-trimester

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Infections of other parts of urinary tract in pregnancy, third trimester

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, 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 O23.33 in its code family, with their registry titles.

View all codes in the O23 family