F50.00 — Anorexia Nervosa, Restricting Type

Clinical Description

F50.00 identifies anorexia nervosa with the restricting subtype, where weight loss is achieved primarily through dieting, fasting, or excessive exercise without binge-eating or purging behaviors. Documentation must address weight status, body image disturbance, and medical stability.

Key Symptoms to Document

When using F50.00, your documentation should reference these symptoms:

• Restriction of energy intake leading to significantly low body weight
• Intense fear of gaining weight or becoming fat
• Disturbance in body image or self-evaluation unduly influenced by body weight/shape
• Denial of the seriousness of current low body weight
• Food rituals, calorie counting, or avoidance of specific food groups
• Excessive exercise or physical restlessness

Common Interventions to Document

Evidence-based interventions typically documented with this diagnosis:

• Family-Based Treatment (FBT/Maudsley Approach) for adolescents
• CBT-E (Enhanced Cognitive Behavioral Therapy for eating disorders)
• Nutritional rehabilitation and meal planning with a dietitian
• Medical monitoring (vital signs, labs, EKG)
• Individual psychotherapy addressing body image and perfectionism

CPT Code Pairings

Common CPT codes used when billing with F50.00:

• 90791 — Psychiatric diagnostic evaluation
• 90837 — Individual psychotherapy, 60 minutes
• 90847 — Family psychotherapy with patient present
• 99214 — Office visit, moderate complexity (medical monitoring)
• 97802 — Medical nutrition therapy, initial assessment

Documentation Tips

• Record BMI and percentage of expected body weight to establish severity (mild: BMI >= 17, moderate: 16-16.99, severe: 15-15.99, extreme: <15).
• Document absence of binge-eating and purging behaviors in the last 3 months to justify the restricting subtype.
• Note medical complications: bradycardia, hypothermia, electrolyte abnormalities, amenorrhea, orthostatic hypotension.
• Assess level of care needed using APA or AED guidelines — document rationale for outpatient vs. higher level of care.
• Record the patient's level of insight and motivation for treatment, as ambivalence is common.

Differential Diagnosis Considerations

When documenting F50.00, consider and rule out:

• Avoidant/Restrictive Food Intake Disorder (ARFID) (F50.82)
• Bulimia nervosa (F50.2)
• Major depressive disorder with appetite loss (F32.x)
• Medical conditions causing weight loss (malabsorption, hyperthyroidism, malignancy)
• Body dysmorphic disorder (F45.22)

Screening Tools

Standardized measures commonly used with this diagnosis:

• EDE-Q (Eating Disorder Examination Questionnaire)
• SCOFF Questionnaire
• EAT-26 (Eating Attitudes Test)
• CIA (Clinical Impairment Assessment)
• Body Shape Questionnaire (BSQ)