Appendicitis ICD-10-CM Codes | 2023

Discover accurate ICD-10-CM codes for Appendicitis, ensuring precise diagnosis and effective medical billing. Simplify coding with our comprehensive resource.

By Patricia Buenaventura on Feb 29, 2024.

Fact Checked by Nate Lacson.

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Appendicitis ICD-10-CM Codes | 2023

What ICD-10 Codes are Used for Appendicitis?

Appendicitis is a common condition characterized by inflammation of the appendix, usually due to obstruction. Accurate ICD-10 codes are essential for effective diagnosis and proper medical coding. Here are some commonly used codes for appendicitis, along with brief clinical descriptions:

K35.0 - Acute appendicitis:

This code is used when the appendix shows inflammation and acute infection. It indicates sudden onset of symptoms such as abdominal pain, tenderness, and fever.

K35.1 - Chronic or recurrent appendicitis:

This code is assigned when there is evidence of chronic or recurrent inflammation of the appendix. Patients may experience intermittent abdominal pain or discomfort.

K35.2 - Acute appendicitis with generalized peritonitis:

This code is used when appendicitis leads to widespread inflammation of the peritoneum, the abdominal cavity's lining. It implies a severe and potentially life-threatening condition.

K35.3 - Acute appendicitis with localized peritonitis:

This code indicates that the inflammation caused by appendicitis is limited to a specific peritoneum area, usually near the appendix.

K35.8 - Other specified acute appendicitis:

This code is assigned when the type of acute appendicitis has specific characteristics or features not covered by the other codes.

K35.9 - Acute appendicitis, unspecified:

This code is used when the documentation does not specify the type of acute appendicitis.

K37.0 - Appendiceal abscess:

This code is assigned when an abscess, a localized collection of pus, forms in or around the appendix. It indicates a more severe form of appendicitis.

K37.1 - Appendicitis with peritoneal abscess:

This code is used when appendicitis leads to the formation of an abscess in the peritoneal cavity, indicating a more extensive infection.

K37.2 - Appendicitis with peritoneal abscess, without rupture:

This code is assigned when an abscess is present but it has yet to rupture.

K37.3 - Appendicitis with peritoneal abscess, with rupture:

This code is used when the abscess associated with appendicitis has ruptured, spreading infection within the abdominal cavity.

Which Appendicitis ICD codes are Billable? 

K35.0 - Acute appendicitis:

Yes. This code is billable as it represents the diagnosis of acute appendicitis, which requires medical intervention and treatment.

K35.1 - Chronic or recurrent appendicitis:

Yes. This code is billable as it denotes the diagnosis of chronic or recurrent inflammation of the appendix, requiring ongoing management and medical attention.

K35.2 - Acute appendicitis with generalized peritonitis:

Yes. This code is billable as it indicates a severe form of appendicitis with widespread inflammation of the peritoneum, necessitating urgent medical intervention.

K35.3 - Acute appendicitis with localized peritonitis:

Yes. This code is billable as it signifies the diagnosis of acute appendicitis with localized inflammation of the peritoneum, requiring medical treatment and monitoring.

K35.8 - Other specified acute appendicitis:

Yes. This code is billable as it covers specific characteristics or features of acute appendicitis not addressed by other codes, still requiring medical attention.

K35.9 - Acute appendicitis, unspecified:

Yes. This code is billable as it is used when the documentation does not specify the type of acute appendicitis but still represents a valid diagnosis that requires medical evaluation and care.

K37.0 - Appendiceal abscess:

Yes. This code is billable as it represents the diagnosis of an abscess formation in or around the appendix, necessitating medical intervention such as drainage or surgical treatment.

K37.1 - Appendicitis with peritoneal abscess:

Yes. This code is billable as it signifies the diagnosis of appendicitis complicated by an abscess within the peritoneal cavity, requiring additional medical management and intervention.

K37.2 - Appendicitis with peritoneal abscess, without rupture

Yes. This code is billable as it represents appendicitis complicated by an abscess that has not yet ruptured, requiring medical attention and potential drainage.

K37.3 - Appendicitis with peritoneal abscess, with rupture:

Yes. This code is billable as it indicates appendicitis complicated by a ruptured abscess, requiring urgent medical intervention, drainage, and management of the associated complications.

Clinical Information

  • Appendicitis is an inflammation of the appendix, a small pouch-like organ located in the lower right side of the abdomen.
  • It is most commonly caused by obstruction of the appendix, leading to bacterial overgrowth and infection.
  • The typical clinical presentation includes sudden-onset abdominal pain, usually starting around the belly button and moving to the lower right side of the abdomen.
  • Other common symptoms include loss of appetite, nausea, vomiting, low-grade fever, and tenderness in the right lower quadrant of the abdomen.
  • Physical examination findings often include rebound tenderness, guarding, and localized tenderness upon palpation of the abdomen.
  • Diagnostic imaging studies such as ultrasound or computed tomography (CT) scans may be utilized to confirm the diagnosis or rule out other conditions.
  • Prompt surgical intervention is the standard treatment for appendicitis, usually involving laparoscopic or open appendectomy.
  • If left untreated, appendicitis can lead to complications like rupture, abscess formation, or peritonitis, which can be life-threatening.
  • Postoperative recovery is generally smooth, and most patients can resume normal activities within a few weeks after surgery.
  • It is crucial to seek medical attention promptly if appendicitis is suspected, as early diagnosis and treatment are vital to prevent complications and ensure a successful recovery.

Synonyms Include:

  • Appendiceal inflammation
  • Appendiceal infection
  • Acute vermiform appendix inflammation
  • Acute appendicitis
  • Inflammation of the cecal appendix
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Commonly asked questions

Can I use an unspecified appendicitis code?

It is recommended to use specific codes whenever possible. However, if the documentation does not specify the type of appendicitis, the code K35.9 (acute appendicitis, unspecified) can be used.

Do appendicitis ICD codes require additional documentation?

Accurate and detailed clinical documentation is essential to support the chosen ICD code. It should include information on the type of appendicitis, any complications or associated conditions, and relevant diagnostic findings.

Are there separate codes for appendectomy procedures?

There are separate procedural codes to document and bill for appendectomy procedures. These codes are found in the Current Procedural Terminology (CPT) system, distinct from ICD codes used for diagnoses.

How often are the ICD codes updated?

The ICD codes are periodically updated by the World Health Organization (WHO). Revisions and updates are released every few years to accommodate new medical knowledge and changes in healthcare practices.

Can an incorrect ICD code affect medical billing and reimbursement?

Yes, using incorrect or inappropriate ICD codes can lead to claim denials, delays in reimbursement, or incorrect billing. Assigning the most accurate and specific code supported by the clinical documentation is crucial.

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