Gastroenterology Coding Alert

Question: I need some guidance on when I use a combination code for diabetes and its complications. Can I assume a causal relationship even if the provider has not documented “with” or “due to” in the note?

Connecticut Subscriber

Answer: Whether you can assume a causal relationship depends on the GI condition and what the provider included in their notes.

ICD-10 guidelines tell you that “a combination code is a single code used to classify: two diagnoses, or a diagnosis with an associated secondary process (manifestation) [and/or a] diagnosis with an associated complication. Combination codes are identified by referring to sub term entries in the Alphabetic Index and by reading the inclusion and exclusion notes in the Tabular List. Assign only the combination code when that code fully identifies the diagnostic conditions involved or when the Alphabetic Index so directs.”

You will find numerous conditions listed in the index under type 2 diabetes that are linked by the word “with,” which tells you that a combination code exists for both conditions when they co-exist. So, if gastroparesis is the potentially related condition, you can assume a causal relationship and code to E11.43 (Type 2 diabetes mellitus with diabetic autonomic (poly)neuropathy). Nonalcoholic fatty liver disease (NAFLD) is condition on the other hand that while often associated with type 2 diabetes, is something your provider would have to explicitly link.

All told, provider documentation is key to code choice in these situations. If in doubt, you should ask your provider.