DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

K35 Acute appendicitis

  • Header · not billable

K35 is not billable. The category heads 13 billable codes in FY2027, grouped under 3 subdivisions.

Index → code

  • Rupture, rupturedappendix (with peritonitis) → K35.32
  • Perforation, perforated (nontraumatic) (of)cecum → K35.32
  • Perforation, perforated (nontraumatic) (of)appendix → K35.32

Where it sits

  1. Chapter 11 Diseases of the digestive system (K00-K95)
  2. K35-K38 Diseases of appendix (K35-K38)
  3. K35 Acute appendicitis
Billable codes
13
Subdivisions
3
CC / MCC codes
8 / 5
HCC V28 codes
0
New FY2027
0
Index entries
61

Codes in K35

  1. K35.2
    Acute appendicitis with generalized peritonitis
    Header
  2. K35.20
    Acute appendicitis with generalized peritonitis, without abscess
    Header
  3. K35.200
    Acute appendicitis with generalized peritonitis, without perforation or abscess
    BillableCC
    Inclusion terms 1

    Inclusion terms

    • (Acute) appendicitis with generalized peritonitis without rupture or perforation of appendix NOS
  4. K35.201
    Acute appendicitis with generalized peritonitis, with perforation, without abscess
    BillableCC
    Inclusion terms 1

    Inclusion terms

    • Appendicitis (acute) with generalized (diffuse) peritonitis following rupture or perforation of appendix NOS
  5. K35.209
    Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation
    BillableCC
    Inclusion terms 1

    Inclusion terms

    • (Acute) appendicitis with generalized peritonitis NOS
  6. K35.21
    Acute appendicitis with generalized peritonitis, with abscess
    Header
  7. K35.210
    Acute appendicitis with generalized peritonitis, without perforation, with abscess
    BillableMCC
    Inclusion terms 1

    Inclusion terms

    • (Acute) appendicitis with generalized peritonitis without rupture or perforation of appendix, with abscess
  8. K35.211
    Acute appendicitis with generalized peritonitis, with perforation and abscess
    BillableMCC
    Inclusion terms 1

    Inclusion terms

    • Appendicitis (acute) with generalized (diffuse) peritonitis following rupture or perforation of appendix, with abscess
  9. K35.219
    Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforation
    BillableMCC
    Inclusion terms 1

    Inclusion terms

    • (Acute) appendicitis with generalized peritonitis and abscess NOS
  10. K35.3
    Acute appendicitis with localized peritonitis
    Header
  11. K35.30
    Acute appendicitis with localized peritonitis, without perforation or gangrene
    BillableCC
    Inclusion terms 1

    Inclusion terms

    • Acute appendicitis with localized peritonitis NOS
  12. K35.31
    Acute appendicitis with localized peritonitis and gangrene, without perforation
    BillableCC
  13. K35.32
    Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscess
    BillableMCC
    Inclusion terms 3

    Inclusion terms

    • (Acute) appendicitis with perforation NOS
    • Perforated appendix NOS
    • Ruptured appendix (with localized peritonitis) NOS
  14. K35.33
    Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess
    BillableMCC
    Inclusion terms 2

    Inclusion terms

    • (Acute) appendicitis with (peritoneal) abscess NOS
    • Ruptured appendix with localized peritonitis and abscess
  15. K35.8
    Other and unspecified acute appendicitis
    Header
  16. K35.80
    Unspecified acute appendicitis
    BillableCC
    Inclusion terms 2

    Inclusion terms

    • Acute appendicitis NOS
    • Acute appendicitis without (localized) (generalized) peritonitis
  17. K35.89
    Other acute appendicitis
    Header
  18. K35.890
    Other acute appendicitis without perforation or gangrene
    BillableCC
  19. K35.891
    Other acute appendicitis without perforation, with gangrene
    BillableCC
    Inclusion terms 1

    Inclusion terms

    • (Acute) appendicitis with gangrene 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

Notes that also apply

Chapter 11 instructions (Excludes2 8): printed on the chapter 11 page.

Index entries

  • Appendicitis (pneumococcal) (retrocecal)ruptured NOS (with localized peritonitis) → K35.32
  • Perforation, perforated (nontraumatic) (of)appendix → K35.32
  • Perforation, perforated (nontraumatic) (of)cecum → K35.32
  • Rupture, rupturedappendix (with peritonitis) → K35.32
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)appendix → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)cecum → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)ileocecal → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)periappendicular → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)pericecal → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)perityphlic → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)postcecal → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)subcecal → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)vermiform appendix → K35.33
  • Appendicitis (pneumococcal) (retrocecal)acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative) → K35.80
  • Gangrene, gangrenous (connective tissue) (dropsical) (dry) (moist) (skin) (ulcer)appendix → K35.80
  • Appendicitis (pneumococcal) (retrocecal)withperforation NOS → K35.32
  • Perforation, perforated (nontraumatic) (of)appendixwith localized peritonitis → K35.32
  • Perforation, perforated (nontraumatic) (of)cecumwith localized peritonitis → K35.32
  • Rupture, rupturedappendix (with peritonitis)with localized peritonitis → K35.32
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)iliac (region)fossa → K35.33
  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic)peritoneum, peritoneal (perforated) (ruptured)with appendicitis → K35.33
  • Appendicitis (pneumococcal) (retrocecal)withperitoneal abscess → K35.33
  • Appendicitis (pneumococcal) (retrocecal)withperitonitis NEC → K35.33
  • Rupture, rupturedcecum (with peritonitis)with peritoneal abscess → K35.33
  • Appendicitis (pneumococcal) (retrocecal)acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative)specified NEC → K35.890
  • Appendicitis (pneumococcal) (retrocecal)withgangrene → K35.891
  • Appendicitis (pneumococcal) (retrocecal)withperitonitis NECgeneralized → K35.209
  • Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion)with or followingappendicitisgeneralized → K35.209
  • Appendicitis (pneumococcal) (retrocecal)withperitonitis NEClocalized → K35.30
  • Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion)with or followingappendicitislocalized → K35.30
  • Appendicitis (pneumococcal) (retrocecal)withgangrenewith localized peritonitis → K35.31
  • Gangrene, gangrenous (connective tissue) (dropsical) (dry) (moist) (skin) (ulcer)appendixwithperitonitis, localized → K35.31
  • Appendicitis (pneumococcal) (retrocecal)withperitonitis NECrupture (with localized peritonitis) → K35.32
  • Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion)with or followingappendicitiswith perforation or rupture → K35.32
  • Appendicitis (pneumococcal) (retrocecal)acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative)withperitoneal abscess → K35.33
  • Appendicitis (pneumococcal) (retrocecal)acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative)withperitonitis NEC → K35.33
  • Appendicitis (pneumococcal) (retrocecal)acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative)withgangrene → K35.891
  • Appendicitis (pneumococcal) (retrocecal)acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative)specified NECwith gangrene → K35.891
  • Appendicitis (pneumococcal) (retrocecal)withperitonitis NECgeneralizedwithout rupture or perforation of appendix → K35.200
  • Appendicitis (pneumococcal) (retrocecal)withperitonitis NECgeneralizedfollowing rupture or perforation of appendix NOS → K35.201

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

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

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