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Q21.12 ICD-10-CM Code: Patent foramen ovale

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
1 inclusion term · 1 Excludes1 · 1 Excludes2

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.

Excludes1Never report with this code
  • acquired cardiac septal defect (I51.0)
Excludes2Not included here; may be reported together
  • ostium primum atrial septal defect (type I) (Q21.20)
IncludesWhat this code covers
  • Persistent foramen ovale

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 306 — CARDIAC CONGENITAL AND VALVULAR DISORDERS WITH MCC (MDC 05)
  • MS-DRG 307 — CARDIAC CONGENITAL AND VALVULAR DISORDERS WITHOUT MCC (MDC 05)

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 Q21.12 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 Q21.12 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Persistent foramen ovale

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from Q21

Excludes2 — Not Included Here

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

Source: inherited from Q21.1

Coder workflow for Q21.12

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

Before you code Q21.12

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with Q21.12. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in Q21.12’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewI51.0

Consider Q21.12. 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).

Official instructions as workflow

  • Excludes1 — check before selecting Q21.12(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with Q21.12: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareI51.0

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

  • Excludes2 — not part of Q21.12(1 note)

    Coding workflow: The conditions named in this note are not included in Q21.12. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareQ21.20

    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: Both the condition Q21.12 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewI51.0

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 Q21.12 with…

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

The codes most likely to be picked instead of Q21.12 — 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.

  • I51.0— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of acquired cardiac septal defect moves the case to I51.0; the two are not reported together unless documented as unrelated.

    Full comparison: Q21.12 vs I51.0 →

  • Q21.10— 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 “Atrial septal defect, unspecified” takes Q21.10; specificity in the record moves it back here.

    Full comparison: Q21.12 vs Q21.10 →

  • Q21.20— 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 ostium primum atrial septal defect (type I) adds Q21.20; it is not part of this code and both may be reported when both are documented.

    Full comparison: Q21.12 vs Q21.20 →

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

Patent foramen ovale is a billable ICD-10-CM diagnosis code (Q21.12).

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

  • 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 Q21.12 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 Excludes2 note: P29 — Cardiovascular disorders originating in the perinatal period (via Q21.-).

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

Referenced by 1 Use Additional Code instruction: Q87.88 — CTNNB1 syndrome (via Q21.-).

These codes instruct coders to additionally report this code when it applies.

Referenced by 4 Code Also instructions across 3 chapters: I27.21 — Secondary pulmonary arterial hypertension (via Q21.-), I27.83 — Eisenmenger's syndrome (via Q21.1.-), Q87.85 — MED13L syndrome (via Q21.-), Z71.87 — Encounter for pediatric-to-adult transition counseling (via Q21.-).

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

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 51 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 2 MS-DRGs: DRG 306 (MDC 05), DRG 307 (MDC 05).

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

Clinical classification (AHRQ CCSR):MAL001 — Cardiac and circulatory congenital anomalies (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 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.

Q20.1 — Double outlet right ventricle, Q20.2 — Double outlet left ventricle, Q20.3 — Discordant ventriculoarterial connection, Q20.4 — Double inlet ventricle, Q20.5 — Discordant atrioventricular connection, Q20.6 — Isomerism of atrial appendages, Q20.8 — Other congenital malformations of cardiac chambers and connections, Q20.9 — Congenital malformation of cardiac chambers and connections, unspecified, Q21.10 — Atrial septal defect, unspecified, Q21.11 — Secundum atrial septal defect, Q21.13 — Coronary sinus atrial septal defect, Q21.14 — Superior sinus venosus atrial septal defect, Q21.15 — Inferior sinus venosus atrial septal defect, Q21.16 — Sinus venosus atrial septal defect, unspecified, Q21.19 — Other specified atrial septal defect, Q21.20 — Atrioventricular septal defect, unspecified as to partial or complete, Q21.21 — Partial atrioventricular septal defect, Q21.22 — Transitional atrioventricular septal defect, Q21.23 — Complete atrioventricular septal defect, Q21.3 — Tetralogy of Fallot, +30 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Cardiac and circulatory congenital anomalies).

Q20.3 — Discordant ventriculoarterial connection, Q20.4 — Double inlet ventricle, Q20.5 — Discordant atrioventricular connection, Q20.6 — Isomerism of atrial appendages, Q20.8 — Other congenital malformations of cardiac chambers and connections, Q20.9 — Congenital malformation of cardiac chambers and connections, unspecified, Q21.0 — Ventricular septal defect, Q21.1 — Atrial septal defect, Q21.10 — Atrial septal defect, unspecified, Q21.11 — Secundum atrial septal defect, Q21.13 — Coronary sinus atrial septal defect, Q21.14 — Superior sinus venosus atrial septal defect, Q21.15 — Inferior sinus venosus atrial septal defect, Q21.16 — Sinus venosus atrial septal defect, unspecified, Q21.19 — Other specified atrial septal defect, Q21.2 — Atrioventricular septal defect, Q21.20 — Atrioventricular septal defect, unspecified as to partial or complete, Q21.21 — Partial atrioventricular septal defect, Q21.22 — Transitional atrioventricular septal defect, Q21.23 — Complete atrioventricular septal defect, +87 more

Same Index main term, other category

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

Q17.8 — Other specified congenital malformations of ear (auricle, ear), Q17.9 — Congenital malformation of ear, unspecified (ear), Q18.0 — Sinus, fistula and cyst of branchial cleft (closure, branchial cleft NOS, cyst), Q18.1 — Preauricular sinus and cyst (closure, preauricular sinus), Q18.2 — Other branchial cleft malformations (closure, branchial cleft NOS), Q18.8 — Other specified congenital malformations of face and neck (eyebrow), Q18.9 — Congenital malformation of face and neck, unspecified (neck), Q20.0 — Common arterial trunk (truncus arteriosus or communis), Q20.8 — Other congenital malformations of cardiac chambers and connections (band, atrial), Q20.9 — Congenital malformation of cardiac chambers and connections, unspecified (cardiac, chambers), Q22.0 — Pulmonary valve atresia (pulmonary, valve, atresia), Q22.1 — Congenital pulmonary valve stenosis (pulmonary, valve, stenosis), Q22.2 — Congenital pulmonary valve insufficiency (pulmonary, valve, insufficiency), Q22.3 — Other congenital malformations of pulmonary valve (pulmonary, valve), Q22.4 — Congenital tricuspid stenosis (tricuspid, atresia or stenosis), Q22.5 — Ebstein's anomaly (Ebstein's), Q22.6 — Hypoplastic right heart syndrome (heart, obstructive NEC), Q22.9 — Congenital malformation of tricuspid valve, unspecified (tricuspid), Q23.0 — Congenital stenosis of aortic valve (heart, valve NEC, aortic, stenosis), Q23.1 — Congenital insufficiency of aortic valve (heart, valve NEC, aortic, insufficiency), +267 more

Contextual Map

Every relationship of Q21.12 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 Q21.12 with these 6 related codes in Claim Check

Hierarchy

Referenced by Excludes2 notes

Referenced by Use Additional Code instructions

  • Q87.88 — CTNNB1 syndrome[Use Additional Code](via Q21.-): “congenital heart malformations (Q20.0-Q24.9)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Referenced by Code Also instructions

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 05 — Diseases and Disorders of the Circulatory System[MDC crossing]: “Diseases and Disorders of the Circulatory System — 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. 15,708 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries (14)

  • Anomaly, anomalous (congenital) (unspecified type), foramen, Botalli[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Anomaly, anomalous (congenital) (unspecified type), foramen, ovale[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Closure, foramen ovale, imperfect[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Cyanosis, due to, patent foramen botalli[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Cyanosis, due to, persistent foramen ovale[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Foramen ovale (nonclosure) (patent) (persistent)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Imperfect, closure (congenital), foramen, botalli[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Imperfect, closure (congenital), foramen, ovale[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • and 6 more

Nearest codes (19)

Change history

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.

Indexed Clinical Terms (14)

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.

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 20, 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. "Q21.12 — Patent foramen ovale." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/q21.12-patent-foramen-ovale

Change history

  • FY2023 — October 1, 2022
    Added to the code set
    Patent foramen ovale
    FY2023 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to Q21.12 in its code family, with their registry titles.

View all codes in the Q21 family