Anorexia nervosa, restricting type, extreme

This code signifies a severe form of anorexia nervosa characterized by extreme restriction of energy intake, leading to a significantly low body weight. Patients with this subtype do not regularly engage in binge-eating or purging behaviors. The "extreme" specifier indicates a BMI of less than 15 kg/m² or, for children/adolescents, a BMI-for-age percentile less than the 5th percentile.

Apply this code when documentation clearly indicates a diagnosis of anorexia nervosa, restricting type, with objective evidence of extreme severity based on BMI. This is typically used for initial diagnosis and ongoing management of patients presenting with severe malnutrition due to self-imposed dietary limitations. Physician documentation must explicitly state "restricting type" and provide BMI or equivalent severity indicators.

• Ensure the medical record explicitly states "restricting type" and provides objective evidence of extreme severity (e.g., BMI < 15 kg/m²).
• Differentiate carefully from F50.02 (binge-eating/purging type) based on the absence of regular bingeing or purging behaviors.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter.