2021 ICD-10-CM Code K51.9

Ulcerative colitis, unspecified

Version 2021

Not Valid for Submission

K51.9 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of ulcerative colitis, unspecified. The code is not specific and is NOT valid for the year 2021 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Unspecified diagnosis codes like K51.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

ICD-10:K51.9
Short Description:Ulcerative colitis, unspecified
Long Description:Ulcerative colitis, unspecified

Code Classification

Specific Coding for Ulcerative colitis, unspecified

Non-specific codes like K51.9 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10 codes with a higher level of specificity when coding for ulcerative colitis, unspecified:

  • BILLABLE CODE - Use K51.90 for Ulcerative colitis, unspecified, without complications
  • NON-BILLABLE CODE - K51.91 for Ulcerative colitis, unspecified, with complications
  • BILLABLE CODE - Use K51.911 for Ulcerative colitis, unspecified with rectal bleeding
  • BILLABLE CODE - Use K51.912 for Ulcerative colitis, unspecified with intestinal obstruction
  • BILLABLE CODE - Use K51.913 for Ulcerative colitis, unspecified with fistula
  • BILLABLE CODE - Use K51.914 for Ulcerative colitis, unspecified with abscess
  • BILLABLE CODE - Use K51.918 for Ulcerative colitis, unspecified with other complication
  • BILLABLE CODE - Use K51.919 for Ulcerative colitis, unspecified with unspecified complications

Clinical Information

Information for Patients


Ulcerative Colitis

Also called: Colitis, Distal colitis, Pancolitis, Ulcerative proctitis

Ulcerative colitis (UC) is a disease that causes inflammation and sores, called ulcers, in the lining of the rectum and colon. It is one of a group of diseases called inflammatory bowel disease.

UC can happen at any age, but it usually starts between the ages of 15 and 30. It tends to run in families. The most common symptoms are pain in the abdomen and blood or pus in diarrhea. Other symptoms may include

About half of people with UC have mild symptoms.

Doctors use blood tests, stool tests, colonoscopy or sigmoidoscopy, and imaging tests to diagnose UC. Several types of drugs can help control it. Some people have long periods of remission, when they are free of symptoms. In severe cases, doctors must remove the colon.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


[Learn More in MedlinePlus]

Ulcerative colitis Ulcerative colitis is a chronic disorder that affects the digestive system. This condition is characterized by abnormal inflammation of the inner surface of the rectum and colon, which make up most of the length of the large intestine. The inflammation usually causes open sores (ulcers) to develop in the large intestine. Ulcerative colitis usually appears between ages 15 and 30, although it can develop at any age. The inflammation tends to flare up multiple times throughout life, which causes recurring signs and symptoms.The most common symptoms of ulcerative colitis are abdominal pain and cramping and frequent diarrhea, often with blood, pus, or mucus in the stool. Other signs and symptoms include nausea, loss of appetite, fatigue, and fevers. Chronic bleeding from the inflamed and ulcerated intestinal tissue can cause a shortage of red blood cells (anemia) in some affected individuals. People with this disorder have difficulty absorbing enough fluids and nutrients from their diet and often experience weight loss. Affected children usually grow more slowly than normal. Less commonly, ulcerative colitis causes problems with the skin, joints, eyes, kidneys, or liver, which are most likely due to abnormal inflammation.Toxic megacolon is a rare complication of ulcerative colitis that can be life-threatening. Toxic megacolon involves widening of the colon and an overwhelming bacterial infection (sepsis). Ulcerative colitis also increases the risk of developing colon cancer, especially in people whose entire colon is inflamed and in people who have had ulcerative colitis for 8 or more years.Ulcerative colitis is one common form of inflammatory bowel disease (IBD). Another type of IBD, Crohn disease, also causes chronic inflammation of the intestines. Unlike ulcerative colitis, which affects only the inner surface of the large intestine, Crohn disease can cause inflammation in any part of the digestive system, and the inflammation extends deeper into the intestinal tissue.
[Learn More in MedlinePlus]

Code History

  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)