DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

I33 Acute and subacute endocarditis

  • Header · not billable

I33 is not billable. The category heads 2 billable codes in FY2027: the 2 codes directly below it.

Index → code

  • Osler's nodes → I33.0
  • SBE (subacute bacterial endocarditis) → I33.0
  • Node(s)Osler's → I33.0

Where it sits

  1. Chapter 9 Diseases of the circulatory system (I00-I99)
  2. I30-I5A Other forms of heart disease (I30-I5A)
  3. I33 Acute and subacute endocarditis
Billable codes
2
Subdivisions
2
CC / MCC codes
0 / 2
HCC V28 codes
0
New FY2027
0
Index entries
37

Codes in I33

  1. I33.0
    Acute and subacute infective endocarditis
    BillableMCC
    Inclusion terms 8, Use additional code 1

    Inclusion terms

    • Bacterial endocarditis (acute) (subacute)
    • Infective endocarditis (acute) (subacute) NOS
    • Endocarditis lenta (acute) (subacute)
    • Malignant endocarditis (acute) (subacute)
    • Purulent endocarditis (acute) (subacute)
    • Septic endocarditis (acute) (subacute)
    • Ulcerative endocarditis (acute) (subacute)
    • Vegetative endocarditis (acute) (subacute)

    Use additional code

    • code (B95-B97) to identify infectious agent B95 B97
  2. I33.9
    Acute and subacute endocarditis, unspecified
    BillableMCC
    Inclusion terms 6

    Inclusion terms

    • Acute endocarditis NOS
    • Acute myoendocarditis NOS
    • Acute periendocarditis NOS
    • Subacute endocarditis NOS
    • Subacute myoendocarditis NOS
    • Subacute periendocarditis NOS

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 I33

Excludes1

  • acute rheumatic endocarditis (I01.1) I01.1
  • endocarditis NOS (I38) I38

Notes that also apply

Chapter 9 instructions (Excludes2 10): printed on the chapter 9 page.

Index entries

  • Osler's nodes → I33.0
  • SBE (subacute bacterial endocarditis) → I33.0
  • Aneurysm (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)endocardial, infective (any valve) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)bacterial (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)constrictive → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)infectious or infective (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)lenta (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)malignant (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)mycotic (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)pneumococcal (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)purulent (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)septic (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)streptococcal (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)suppurative (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)ulcerative (acute) (any valve) (subacute) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)vegetative (acute) (any valve) (subacute) → I33.0
  • Infection, infected, infective (opportunistic)endocardium → I33.0
  • Node(s)Osler's → I33.0
  • Ulcer, ulcerated, ulcerating, ulceration, ulcerativevalve, heart → I33.0
  • Vegetation, vegetativeendocarditis (acute) (any valve) (subacute) → I33.0
  • Vegetation, vegetativeheart (mycotic) (valve) → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)acute or subacute → I33.9
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)toxic → I33.9
  • Aneurysm (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)infectiveendocardial (any valve) → I33.0
  • Aneurysm (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)mycoticendocardial (any valve) → I33.0
  • Arthropathyin (due to)infective endocarditis → I33.0 [M12.80]
  • Disorder (of)glomerular (in)subacute bacterial endocarditis → I33.0 [N08]
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)acute or subacuteinfective → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)due toSerratia marcescens → I33.0
  • Glomerulonephritisin (due to)subacute bacterial endocarditis → I33.0 [N08]
  • Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic)due tosubacute bacterial endocarditis → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)aortic (heart) (nonrheumatic) (valve)acute or subacute → I33.9
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)pulmonary (chronic) (heart) (valve)acute or subacute → I33.9
  • Arthropathyreactivein (due to)infective endocarditis → I33.0 [M02.9]
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)mitral (chronic) (double) (fibroid) (heart) (inactive) (valve) (with chorea)active or acutebacterial → I33.0
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)mitral (chronic) (double) (fibroid) (heart) (inactive) (valve) (with chorea)nonrheumaticacute or subacute → I33.9
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)tricuspid (chronic) (heart) (inactive) (rheumatic) (valve) (with chorea)nonrheumaticacute or subacute → I33.9

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

Hierarchy