F34.0
BillableCyclothymic disorder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F34.0 an HCC code?
No. F34.0 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for F34.0
For F34.0 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed F34.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F34.0 is the ICD-10-CM diagnosis code for cyclothymic disorder. A chronic mood disorder characterized by alternating periods of elevated mood and depression that are less severe than bipolar disorder. F34.0 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering mood [affective] disorders (f30-f39).
F34.0 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.
Does NOT map to any HCC in V28 or V24 (no RAF contribution in either model). Cyclothymic disorder has no risk adjustment value in either model, which is notable given its bipolar spectrum classification. If the patient's condition evolves to meet bipolar II criteria (F31.81), it would capture HCC 154 in V28 and HCC 59 in V24.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for F34.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Cyclothymia is a persistent condition with mood fluctuations; ensure documentation distinguishes it from bipolar disorder
- •This condition typically lasts for years and requires long-term management
Clinical Significance
Cyclothymic disorder is a chronic mood disturbance involving numerous periods of hypomanic symptoms and depressive symptoms that do not meet criteria for a full hypomanic or major depressive episode. This condition is part of the bipolar spectrum but distinct from bipolar I and II. It represents a chronic low-grade mood instability that can significantly impact quality of life and may evolve into bipolar I or II over time.
Documentation Requirements
- ✓Provider documentation of cyclothymic disorder as a specific diagnosis
- ✓Chronic course of at least 2 years (1 year in adolescents) documented
- ✓Alternating periods of hypomanic and depressive symptoms described
- ✓Symptoms never meeting full criteria for a hypomanic episode, manic episode, or major depressive episode
- ✓Absence of symptom-free periods lasting more than 2 months
- ✓Functional impact documented
- ✓Current treatment plan
Commonly Confused Codes
- •F31.81 — Bipolar II disorder: Full hypomanic and major depressive episodes present
- •F31.89 — Other bipolar disorder: Atypical bipolar presentation that does not fit cyclothymia
- •F34.1 — Dysthymic disorder: Chronic depression without hypomanic symptoms
- •F31.0 — Bipolar disorder, current episode hypomanic: Full hypomanic episode within bipolar disorder