F51.02 ICD-10-CM Code: Adjustment insomnia

F51.02 is the ICD-10-CM diagnosis code for adjustment insomnia. Insomnia that develops as a direct result of a stressful life event or significant change, such as a job loss, relationship problem, or major life transition. The sleep difficulty is temporary and typically resolves once the person adjusts to the new situation. F51.02 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering behavioral syndromes associated with physiological disturbances and physical factors (f50-f59).

F51.02 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Always identify and document the specific stressor or life event triggering the insomnia, as this distinguishes adjustment insomnia from other insomnia types.