DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

Q20 Congenital malformations of cardiac chambers and connections

  • Header · not billable

Q20 is not billable. The category heads 9 billable codes in FY2027: the 9 codes directly below it.

Index → code

  • Unilocular heart → Q20.8
  • Levotransposition → Q20.5
  • Dextraposition, aorta → Q20.3

Where it sits

  1. Chapter 17 Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1)
  2. Q20-Q28 Congenital malformations of the circulatory system (Q20-Q28)
  3. Q20 Congenital malformations of cardiac chambers and connections
Billable codes
9
Subdivisions
9
CC / MCC codes
1 / 5
HCC V28 codes
0
New FY2027
0
Index entries
47

Codes in Q20

  1. Q20.0
    Common arterial trunk
    BillableMCCExempt
    Inclusion terms 1, Excludes1 1

    Inclusion terms

    • Persistent truncus arteriosus

    Excludes1

    • aortic septal defect (Q21.4) Q21.4
  2. Q20.1
    Double outlet right ventricle
    BillableMCCExempt
    Inclusion terms 1

    Inclusion terms

    • Taussig-Bing syndrome
  3. Q20.2
    Double outlet left ventricle
    BillableMCCExempt
  4. Q20.3
    Discordant ventriculoarterial connection
    BillableMCCExempt
    Inclusion terms 2

    Inclusion terms

    • Dextrotransposition of aorta
    • Transposition of great vessels (complete)
  5. Q20.4
    Double inlet ventricle
    BillableMCCExempt
    Inclusion terms 3

    Inclusion terms

    • Common ventricle
    • Cor triloculare biatriatum
    • Single ventricle
  6. Q20.5
    Discordant atrioventricular connection
    BillableCCExempt
    Inclusion terms 3

    Inclusion terms

    • Corrected transposition
    • Levotransposition
    • Ventricular inversion
  7. Q20.6
    Isomerism of atrial appendages
    BillableExempt
    Inclusion terms 1

    Inclusion terms

    • Isomerism of atrial appendages with asplenia or polysplenia
  8. Q20.8
    Other congenital malformations of cardiac chambers and connections
    BillableExempt
    Inclusion terms 1

    Inclusion terms

    • Cor binoculare
  9. Q20.9
    Congenital malformation of cardiac chambers and connections, unspecified
    BillableExempt

CC/MCC: as a secondary diagnosis, unless the principal diagnosis is on the code’s PDX exclusion list (MS-DRG v44 Appendix C; list on the code card).

Sources of each column.

Instructions

At Q20

Excludes1

  • dextrocardia with situs inversus (Q89.3) Q89.3
  • mirror-image atrial arrangement with situs inversus (Q89.3) Q89.3

Notes that also apply

Chapter 17 instructions (Notes 1, Excludes2 1): printed on the chapter 17 page.

Index entries

  • Origin of both great vessels from right ventricle → Q20.1
  • Taussig-Bing syndrome → Q20.1
  • Dextraposition, aorta → Q20.3
  • Dextrotransposition, aorta → Q20.3
  • Corrected transposition → Q20.5
  • Levotransposition → Q20.5
  • Isomerism atrial appendages (with asplenia or polysplenia) → Q20.6
  • Unilocular heart → Q20.8
  • Commonarterial trunk → Q20.0
  • Commontruncus (arteriosus) → Q20.0
  • Persistence, persistent (congenital)truncus arteriosus or communis → Q20.0
  • Truncusarteriosus (persistent) → Q20.0
  • Truncuscommunis → Q20.0
  • ComplexTaussig-Bing (transposition, aorta and overriding pulmonary artery) → Q20.1
  • Defect, defectiveTaussig-Bing (aortic transposition and overriding pulmonary artery) → Q20.1
  • Discordant connectionventriculoarterial → Q20.3
  • Transposition (congenital)aorta (dextra) → Q20.3
  • Transposition (congenital)great vessels (complete) (partial) → Q20.3
  • Transposition (congenital)vessels, great (complete) (partial) → Q20.3
  • Absence (of) (organ or part) (complete or partial)ventricular septum → Q20.4
  • Commonventricle → Q20.4
  • Doubleinlet ventricle → Q20.4
  • Singleventricle → Q20.4
  • Discordant connectionatrioventricular (congenital) → Q20.5
  • Inversionventricular → Q20.5
  • Transposition (congenital)corrected → Q20.5
  • Ventricle, ventricularinversion → Q20.5
  • Corbiloculare → Q20.8
  • Cortriloculare → Q20.8
  • Doubleauricle (heart) → Q20.8
  • Malpositioncongenitalarterial trunk → Q20.0
  • Doubleoutletright ventricle → Q20.1
  • Doubleoutletleft ventricle → Q20.2
  • Absence (of) (organ or part) (complete or partial)septumventricular (congenital) → Q20.4
  • Agenesisseptumventricular → Q20.4
  • Cortrilocularebiatrium → Q20.4
  • Displacement, displacedventricular septumwith rudimentary ventricle → Q20.4
  • Communicationbetweenleft ventricle and right atrium → Q20.5
  • Anomaly, anomalous (congenital) (unspecified type)atrialbands or folds → Q20.8
  • Anomaly, anomalous (congenital) (unspecified type)auricleheart → Q20.8

7 more, longer entries are not listed; the search box finds them by word.

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy