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New FY22 Code: Gastric Intestinal Metaplasia

Intestinal metaplasia (IM) occurs when cells in the tissues of the upper digestive tract, often in the stomach or esophagus, change and become more like cells from the intestines. Intestinal metaplasia in the esophagus is also called Barrett’s esophagus. Intestinal metaplasia is more common in people who have chronic acid reflux or gastroesophageal reflux disease (GERD). The exact cause of intestinal metaplasia is still uncertain. Some healthcare professionals believe an H. pylori infection causes intestinal metaplasia, but there is also a range of risk factors that may increase the risk of developing it. While it is not possible to avoid some risk factors such as genetics, people can avoid other risk factors, including diet, H. pylori infection, and smoking.

Intestinal metaplasia can be severe. The transformation of the cells of the gastric lining puts a person at a much higher risk of developing gastric cancer. It is believed the risk for progression into gastric cancer is highest among patients with diffuse gastric IM (which involves both antrum and body). Once dysplasia is present, the location is less important as there is a higher risk regardless of location. The median time until diagnosis of cancer among the patients with GIM was 4.6 years.

Currently, there is no ICD-10-CM unique code for gastric IM. The October 2021 updates will include 10 new codes in two new subcategories for gastric intestinal metaplasia, one without dysplasia (Table 1) and one with dysplasia (Table 2).

K31.A0Gastric intestinal metaplasia, unspecified
K31.A11Gastric intestinal metaplasia without dysplasia, involving the antrum
K31.A12Gastric intestinal metaplasia without dysplasia, involving the body (corpus)
K31.A13Gastric intestinal metaplasia without dysplasia, involving the fundus
K31.A14Gastric intestinal metaplasia without dysplasia, involving the cardia
K31.A15Gastric intestinal metaplasia without dysplasia, involving multiple sites
K31.A19Gastric intestinal metaplasia without dysplasia, unspecified site
Table 1 Subcategory K31.A Gastric Intestinal Metaplasia
K31.A21Gastric intestinal metaplasia with low grade dysplasia
K31.A22Gastric intestinal metaplasia with high grade dysplasia
K31.A29Gastric intestinal metaplasia with dysplasia unspecified
Table 2 Subcategory K31.A2 Gastric Intestinal Metaplasia with Dysplasia