Gastroenterology Coding Alert

Question: My physician diagnosed a patient with anorexia. I’m confused about how to code for the condition. ICD-10 has two coding options: F50.0- and R63.0. Which is the right one to use?

New York Subscriber

Answer: Coding anorexia can be difficult, especially since colloquially we use the term “anorexia” when what we usually mean is “anorexia nervosa.”

Clinically, anorexia is a medical condition that refers only to a lack or loss of appetite, which is why R63.0 (Anorexia) is a signs and symptoms code in ICD-10. The other codes, under F50.0- (Anorexia nervosa), live in the Mental, Behavioral, and Neurodevelopmental Disorders chapter of ICD-10 because those codes refer to the psychological eating disorder. Which code you will use in your case depends on the practitioner’s notes. If the documentation is vague, you should seek clarification.

Note: In addition, there’s another disorder that presents with symptoms similar to anorexia but is distinctly different, which codes to F50.82 (Avoidant/restrictive food intake disorder). In these cases, patients present with irritable bowel-like symptoms but have restricted their foods so extremely that they become seriously underweight. This condition typically has nothing to do with body image, unlike anorexia nervosa.

Reminder: Code R63.0 is listed in an Excludes1 note for all F50.- (Eating disorders) codes, and conversely F50.0- is listed in an Excludes1 note under R63.0. This is a clue that you’re dealing with conditions that have different etiologies (causes).