MS-DRG · FY 2026 v43.0

MS-DRG 306 – Cardiac Congenital and Valvular Disorders with MCC

A Medical DRG in MDC 05 (Diseases & Disorders of the Circulatory System). Inpatient cases group to DRG 306 when the ICD-10-CM principal diagnosis is one of the 146 codes listed below and a secondary diagnosis on the major complication or comorbidity (MCC) list is present. Its FY 2026 relative weight is 1.5758 with a geometric mean length of stay of 3.8 days.

Medical DRG – assigned by principal diagnosis✓ Official CMS v43.0 dataset
1.5758
Relative Weight
3.8
Geometric Mean LOS (days)
5.2
Arithmetic Mean LOS (days)
146
Principal Diagnosis Codes

Severity family

DRG 306with MCCWeight 1.5758 · GMLOS 3.8 daysDRG 307without MCCWeight 0.9132 · GMLOS 2.2 days
How a case is assigned to DRG 306

The grouper first assigns the case to MDC 05 from the principal diagnosis and finds no qualifying operating-room procedure (this is a Medical DRG; ICD-10-PCS codes do not drive assignment here), then applies the severity split from secondary diagnoses: with MCC → 306; without MCC → 307.

ICD-10-CM

Principal Diagnosis Codes 146 codes · 26 categories

146 of 146 shown
A52 Late syphilis2 codes
  • A52.01 Syphilitic aneurysm of aorta
  • A52.02 Syphilitic aortitis
B33 Other viral diseases, not elsewhere classified1 code
I01 Rheumatic fever with heart involvement1 code
  • I01.1 Acute rheumatic endocarditis
I05 Rheumatic mitral valve diseases5 codes
  • I05.0 Rheumatic mitral stenosis
  • I05.1 Rheumatic mitral insufficiency
  • I05.2 Rheumatic mitral stenosis with insufficiency
  • I05.8 Other rheumatic mitral valve diseases
  • I05.9 Rheumatic mitral valve disease, unspecified
I06 Rheumatic aortic valve diseases5 codes
  • I06.0 Rheumatic aortic stenosis
  • I06.1 Rheumatic aortic insufficiency
  • I06.2 Rheumatic aortic stenosis with insufficiency
  • I06.8 Other rheumatic aortic valve diseases
  • I06.9 Rheumatic aortic valve disease, unspecified
I07 Rheumatic tricuspid valve diseases5 codes
  • I07.0 Rheumatic tricuspid stenosis
  • I07.1 Rheumatic tricuspid insufficiency
  • I07.2 Rheumatic tricuspid stenosis and insufficiency
  • I07.8 Other rheumatic tricuspid valve diseases
  • I07.9 Rheumatic tricuspid valve disease, unspecified
I08 Multiple valve diseases6 codes
  • I08.0 Rheumatic disorders of both mitral and aortic valves
  • I08.1 Rheumatic disorders of both mitral and tricuspid valves
  • I08.2 Rheumatic disorders of both aortic and tricuspid valves
  • I08.3 Combined rheumatic disorders of mitral, aortic and tricuspid valves
  • I08.8 Other rheumatic multiple valve diseases
  • I08.9 Rheumatic multiple valve disease, unspecified
I09 Other rheumatic heart diseases2 codes
  • I09.1 Rheumatic diseases of endocardium, valve unspecified
  • I09.89 Other specified rheumatic heart diseases
I23 Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period)2 codes
  • I23.4 Rupture of chordae tendineae as current complication following acute myocardial infarction
  • I23.5 Rupture of papillary muscle as current complication following acute myocardial infarction
I34 Nonrheumatic mitral valve disorders6 codes
  • I34.0 Nonrheumatic mitral (valve) insufficiency
  • I34.1 Nonrheumatic mitral (valve) prolapse
  • I34.2 Nonrheumatic mitral (valve) stenosis
  • I34.81 Nonrheumatic mitral (valve) annulus calcification
  • I34.89 Other nonrheumatic mitral valve disorders
  • I34.9 Nonrheumatic mitral valve disorder, unspecified
I35 Nonrheumatic aortic valve disorders5 codes
  • I35.0 Nonrheumatic aortic (valve) stenosis
  • I35.1 Nonrheumatic aortic (valve) insufficiency
  • I35.2 Nonrheumatic aortic (valve) stenosis with insufficiency
  • I35.8 Other nonrheumatic aortic valve disorders
  • I35.9 Nonrheumatic aortic valve disorder, unspecified
I36 Nonrheumatic tricuspid valve disorders5 codes
  • I36.0 Nonrheumatic tricuspid (valve) stenosis
  • I36.1 Nonrheumatic tricuspid (valve) insufficiency
  • I36.2 Nonrheumatic tricuspid (valve) stenosis with insufficiency
  • I36.8 Other nonrheumatic tricuspid valve disorders
  • I36.9 Nonrheumatic tricuspid valve disorder, unspecified
I37 Nonrheumatic pulmonary valve disorders5 codes
  • I37.0 Nonrheumatic pulmonary valve stenosis
  • I37.1 Nonrheumatic pulmonary valve insufficiency
  • I37.2 Nonrheumatic pulmonary valve stenosis with insufficiency
  • I37.8 Other nonrheumatic pulmonary valve disorders
  • I37.9 Nonrheumatic pulmonary valve disorder, unspecified
I38 Endocarditis, valve unspecified1 code
  • I38 Endocarditis, valve unspecified
I39 Endocarditis and heart valve disorders in diseases classified elsewhere1 code
  • I39 Endocarditis and heart valve disorders in diseases classified elsewhere
I51 Complications and ill-defined descriptions of heart disease2 codes
  • I51.1 Rupture of chordae tendineae, not elsewhere classified
  • I51.2 Rupture of papillary muscle, not elsewhere classified
Q20 Congenital malformations of cardiac chambers and connections9 codes
  • Q20.0 Common arterial trunk
  • 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 Congenital malformations of cardiac septa17 codes
  • Q21.0 Ventricular septal defect
  • Q21.10 Atrial septal defect, unspecified
  • Q21.11 Secundum atrial septal defect
  • Q21.12 Patent foramen ovale
  • 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
  • Q21.4 Aortopulmonary septal defect
  • Q21.8 Other congenital malformations of cardiac septa
  • Q21.9 Congenital malformation of cardiac septum, unspecified
Q22 Congenital malformations of pulmonary and tricuspid valves9 codes
  • Q22.0 Pulmonary valve atresia
  • Q22.1 Congenital pulmonary valve stenosis
  • Q22.2 Congenital pulmonary valve insufficiency
  • Q22.3 Other congenital malformations of pulmonary valve
  • Q22.4 Congenital tricuspid stenosis
  • Q22.5 Ebstein's anomaly
  • Q22.6 Hypoplastic right heart syndrome
  • Q22.8 Other congenital malformations of tricuspid valve
  • Q22.9 Congenital malformation of tricuspid valve, unspecified
Q23 Congenital malformations of aortic and mitral valves9 codes
  • Q23.0 Congenital stenosis of aortic valve
  • Q23.1 Congenital insufficiency of aortic valve
  • Q23.2 Congenital mitral stenosis
  • Q23.3 Congenital mitral insufficiency
  • Q23.4 Hypoplastic left heart syndrome
  • Q23.81 Bicuspid aortic valve
  • Q23.82 Congenital mitral valve cleft leaflet
  • Q23.88 Other congenital malformations of aortic and mitral valves
  • Q23.9 Congenital malformation of aortic and mitral valves, unspecified
Q24 Other congenital malformations of heart8 codes
  • Q24.0 Dextrocardia
  • Q24.1 Levocardia
  • Q24.2 Cor triatriatum
  • Q24.3 Pulmonary infundibular stenosis
  • Q24.4 Congenital subaortic stenosis
  • Q24.5 Malformation of coronary vessels
  • Q24.8 Other specified congenital malformations of heart
  • Q24.9 Congenital malformation of heart, unspecified
Q25 Congenital malformations of great arteries22 codes
  • Q25.0 Patent ductus arteriosus
  • Q25.1 Coarctation of aorta
  • Q25.21 Interruption of aortic arch
  • Q25.29 Other atresia of aorta
  • Q25.3 Supravalvular aortic stenosis
  • Q25.40 Congenital malformation of aorta unspecified
  • Q25.41 Absence and aplasia of aorta
  • Q25.42 Hypoplasia of aorta
  • Q25.43 Congenital aneurysm of aorta
  • Q25.44 Congenital dilation of aorta
  • Q25.45 Double aortic arch
  • Q25.46 Tortuous aortic arch
  • Q25.47 Right aortic arch
  • Q25.48 Anomalous origin of subclavian artery
  • Q25.49 Other congenital malformations of aorta
  • Q25.5 Atresia of pulmonary artery
  • Q25.6 Stenosis of pulmonary artery
  • Q25.71 Coarctation of pulmonary artery
  • Q25.72 Congenital pulmonary arteriovenous malformation
  • Q25.79 Other congenital malformations of pulmonary artery
  • Q25.8 Other congenital malformations of other great arteries
  • Q25.9 Congenital malformation of great arteries, unspecified
Q26 Congenital malformations of great veins7 codes
  • Q26.0 Congenital stenosis of vena cava
  • Q26.1 Persistent left superior vena cava
  • Q26.2 Total anomalous pulmonary venous connection
  • Q26.3 Partial anomalous pulmonary venous connection
  • Q26.4 Anomalous pulmonary venous connection, unspecified
  • Q26.8 Other congenital malformations of great veins
  • Q26.9 Congenital malformation of great vein, unspecified
Q87 Other specified congenital malformation syndromes affecting multiple systems5 codes
  • Q87.40 Marfan syndrome, unspecified
  • Q87.410 Marfan syndrome with aortic dilation
  • Q87.418 Marfan syndrome with other cardiovascular manifestations
  • Q87.42 Marfan syndrome with ocular manifestations
  • Q87.43 Marfan syndrome with skeletal manifestation
R01 Cardiac murmurs and other cardiac sounds2 codes
  • R01.0 Benign and innocent cardiac murmurs
  • R01.1 Cardiac murmur, unspecified
T82 Complications of cardiac and vascular prosthetic devices, implants and grafts4 codes
  • T82.01XA Breakdown (mechanical) of heart valve prosthesis, initial encounter
  • T82.02XA Displacement of heart valve prosthesis, initial encounter
  • T82.03XA Leakage of heart valve prosthesis, initial encounter
  • T82.09XA Other mechanical complication of heart valve prosthesis, initial encounter
ICD-10-PCS

Procedure Codes

Procedure codes do not drive assignment for this DRG. DRG 306 is a Medical DRG, assigned from the principal diagnosis above.

Frequently Asked Questions

What is MS-DRG 306?

MS-DRG 306 (Cardiac Congenital and Valvular Disorders with MCC) is a medical DRG in MDC 05 (Diseases & Disorders of the Circulatory System). Its FY 2026 relative weight is 1.5758 with a geometric mean length of stay of 3.8 days.

What is the difference between DRG 306, 307?

All 2 share the same base category; the severity of secondary diagnoses separates them: 306 (with MCC), 307 (without MCC). A major complication or comorbidity (MCC) places the case in the highest-weighted DRG of the family; a CC in the middle; neither in the lowest.

How many diagnosis codes group to DRG 306?

146 ICD-10-CM principal diagnosis codes group to this DRG, spanning 26 three-character categories.

What is the relative weight of DRG 306?

The FY 2026 relative weight of this DRG is 1.5758, meaning reimbursement of roughly 1.58 times the average Medicare inpatient case. Multiply by a hospital's blended base rate for the approximate payment.

← PreviousDRG 305 – Hypertension without MCC
Source: CMS ICD-10 MS-DRG v43.0 Definitions Manual and the FY 2026 IPPS Final Rule (Table 5), effective October 1, 2025 through September 30, 2026. We publish the DRG assignments as CMS defines them and add the navigation, search, and code links.