Bipolar Disorder Treatment Coding and Billing

Bipolar Disorder Coding Overview

Bipolar disorder uses ICD-10 codes F31.0 through F31.9 depending on the current episode type (manic, depressive, mixed, in remission). The specific episode code determines medical necessity for treatment intensity. F31.9 (unspecified) triggers more payer scrutiny than episode-specific codes. Always code to the highest specificity supported by clinical documentation.

Common CPT Codes for Bipolar Treatment

1. 90837 (60-minute psychotherapy) for individual therapy sessions addressing mood stabilization, episode management, and relapse prevention.
2. 99214/99215 (E/M codes) for psychiatric medication management visits — mood stabilizers, antipsychotics, and antidepressant monitoring.
3. 90834 (45-minute psychotherapy) for maintenance sessions between acute episodes.
4. 90853 (group psychotherapy) for peer support and skills-based group work.

Payer Coverage Notes

UnitedHealthcare covers bipolar treatment under standard behavioral health benefits. Prior auth is required for sessions beyond the initial evaluation. Anthem requires a treatment plan update every 90 days during active episodes. Aetna covers 90837 at full reimbursement for manic/depressive episodes (F31.1-F31.5). Medicare Part B covers psychiatric services for bipolar disorder without session limits when documented as medically necessary.

Common Denials

CO-50 occurs when prior auth is missing for ongoing therapy. CO-39 flags session limits. Appeal session limit denials citing parity — if the plan covers unlimited medical visits, it must cover comparable mental health visits under MHPAEA. See behavioral health denial appeals and medical necessity rules.