2019 ICD-10-CM Diagnosis Code K35.21

Acute appendicitis with generalized peritonitis, with abscess

    2019 - New Code Billable/Specific Code
  • K35.21 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • Short description: Acute appendicitis with gen peritonitis, with abscess
  • ICD-10-CM K35.21 is a new 2019 ICD-10-CM code that became effective on October 1, 2018.
  • This is the American ICD-10-CM version of K35.21 - other international versions of ICD-10 K35.21 may differ.
The following code(s) above K35.21 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to K35.21:
  • K00-K95
    2019 ICD-10-CM Range K00-K95

    Diseases of the digestive system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the digestive system
  • K35.2
    ICD-10-CM Diagnosis Code K35.2

    Acute appendicitis with generalized peritonitis

      2016 2017 2018 2019 - Deleted Code 2019 - New Code Non-Billable/Non-Specific Code
    Applicable To
    • Appendicitis (acute) with generalized (diffuse) peritonitis following rupture or perforation of appendix
    Acute appendicitis with generalized peritonitis
ICD-10-CM K35.21 is grouped within Diagnostic Related Group(s) (MS-DRG v36.0):
  • 338 Appendectomy with complicated principal diagnosis with mcc
  • 339 Appendectomy with complicated principal diagnosis with cc
  • 340 Appendectomy with complicated principal diagnosis without cc/mcc
  • 371 Major gastrointestinal disorders and peritoneal infections with mcc
  • 372 Major gastrointestinal disorders and peritoneal infections with cc
  • 373 Major gastrointestinal disorders and peritoneal infections without cc/mcc
Code History
  • 2019 (effective 10/1/2018): New code

Diagnosis Index entries containing back-references to K35.21:
  • Appendicitis (pneumococcal) (retrocecal) K37
    ICD-10-CM Diagnosis Code K37

    Unspecified appendicitis

      2016 2017 2018 2019 Billable/Specific Code
    Type 1 Excludes
    • with
      • peritonitis NEC K35.33
        ICD-10-CM Diagnosis Code K35.33

        Acute appendicitis with perforation and localized peritonitis, with abscess

          2019 - New Code Billable/Specific Code
        Applicable To
        • (Acute) appendicitis with (peritoneal) abscess NOS
        • Ruptured appendix with localized peritonitis and abscess
        • generalized (with perforation or rupture) K35.20
          ICD-10-CM Diagnosis Code K35.20

          Acute appendicitis with generalized peritonitis, without abscess

            2019 - New Code Billable/Specific Code
          Applicable To
          • (Acute) appendicitis with generalized peritonitis NOS
          • with abscess K35.21
    • acute (catarrhal) (fulminating) (gangrenous) (obstructive) (retrocecal) (suppurative) K35.80
      ICD-10-CM Diagnosis Code K35.80

      Unspecified acute appendicitis

        2016 2017 2018 2019 Billable/Specific Code
      Applicable To
      • Acute appendicitis NOS
      • Acute appendicitis without (localized) (generalized) peritonitis
      • with
        • peritonitis NEC K35.33
          ICD-10-CM Diagnosis Code K35.33

          Acute appendicitis with perforation and localized peritonitis, with abscess

            2019 - New Code Billable/Specific Code
          Applicable To
          • (Acute) appendicitis with (peritoneal) abscess NOS
          • Ruptured appendix with localized peritonitis and abscess
          • generalized (with perforation or rupture) K35.20
            ICD-10-CM Diagnosis Code K35.20

            Acute appendicitis with generalized peritonitis, without abscess

              2019 - New Code Billable/Specific Code
            Applicable To
            • (Acute) appendicitis with generalized peritonitis NOS
            • with abscess K35.21

ICD-10-CM Codes Adjacent To K35.21
K31.811 …… with bleeding
K31.819 …… without bleeding
K31.82 Dieulafoy lesion (hemorrhagic) of stomach and duodenum
K31.83 Achlorhydria
K31.84 Gastroparesis
K31.89 Other diseases of stomach and duodenum
K31.9 Disease of stomach and duodenum, unspecified
K35 Acute appendicitis
K35.2 Acute appendicitis with generalized peritonitis
K35.20 …… without abscess
K35.21 …… with abscess
K35.3 Acute appendicitis with localized peritonitis
K35.30 …… without perforation or gangrene
K35.31 …… and gangrene, without perforation
K35.32 Acute appendicitis with perforation and localized peritonitis, without abscess
K35.33 Acute appendicitis with perforation and localized peritonitis, with abscess
K35.8 Other and unspecified acute appendicitis
K35.80 Unspecified acute appendicitis
K35.89 Other acute appendicitis
K35.890 …… without perforation or gangrene
K35.891 …… without perforation, with gangrene

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.