ICD-10-CM Codes
K00-K95 Diseases of the digestive system
K35-K38 Diseases of appendix
K35- Acute appendicitis
2021 ICD-10-CM Diagnosis Code K35

2021 ICD-10-CM Diagnosis Code K35

Acute appendicitis

2016

2017

2018

2019

2020

2021

Non-Billable/Non-Specific Code

K35 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
The 2021 edition of ICD-10-CM K35 became effective on October 1, 2020.
This is the American ICD-10-CM version of K35 - other international versions of ICD-10 K35 may differ.

The following code(s) above K35 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:

K00-K95
2021 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

Clinical Information

A disorder characterized by acute inflammation to the vermiform appendix caused by a pathogenic agent.
Acute inflammation of the vermiform appendix.

Code History

2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
2017 (effective 10/1/2016): No change
2018 (effective 10/1/2017): No change
2019 (effective 10/1/2018): No change
2020 (effective 10/1/2019): No change
2021 (effective 10/1/2020): No change

Code annotations containing back-references to K35:

Type 1 Excludes: K65

ICD-10-CM Diagnosis Code K65
Peritonitis
Code Also
- if applicable diverticular disease of intestine (K57.-)
Type 1 Excludes
- acute appendicitis with generalized peritonitis (K35.2-)
- aseptic peritonitis (T81.6)
- benign paroxysmal peritonitis (E85.0)
- chemical peritonitis (T81.6)
- gonococcal peritonitis (A54.85)
- neonatal peritonitis (P78.0-P78.1)
- pelvic peritonitis, female (N73.3-N73.5)
- periodic familial peritonitis (E85.0)
- peritonitis due to talc or other foreign substance (T81.6)
- peritonitis in chlamydia (A74.81)
- peritonitis in diphtheria (A36.89)
- peritonitis in syphilis (late) (A52.74)
- peritonitis in tuberculosis (A18.31)
- peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
- peritonitis with or following appendicitis (K35.-)
- puerperal peritonitis (O85)
- retroperitoneal infections (K68.-)
Use Additional
- code (B95-B97), to identify infectious agent, if known

ICD-10-CM Codes Adjacent To K35

K31.7 Polyp of stomach and duodenum

K31.8 Other specified diseases of stomach and duodenum

K31.81 Angiodysplasia of stomach and duodenum

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

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

2021 ICD-10-CM Diagnosis Code K35

Acute appendicitis

Diseases of the digestive system

Peritonitis