Injection of recombinant human fibrinogen concentrate (Fesilty), billed per 1 mg

Human fibrinogen-chmt (Fesilty) is a recombinant human fibrinogen concentrate indicated for the treatment of acute bleeding episodes in adults with congenital fibrinogen deficiency, including afibrinogenemia and hypofibrinogenemia. This code is billed per 1 mg of the drug administered via injection. Fesilty works by temporarily replacing or supplementing fibrinogen, a critical clotting factor, to restore hemostasis.

This code applies when Fesilty is administered in an outpatient or physician office setting for patients with documented congenital fibrinogen deficiency experiencing acute bleeding or requiring perioperative prophylaxis. Documentation should include the confirmed diagnosis of afibrinogenemia or hypofibrinogenemia, the dose administered in milligrams, and the clinical indication (acute bleed vs. surgical prophylaxis). Units billed must reflect the total milligrams administered, as this is a per-mg code.

• Unit calculation is critical: Bill one unit per 1 mg administered; verify the total dose in the administration record and confirm mg (not vials or grams) to avoid underbilling or overbilling.
• Do not confuse with other fibrinogen products: Codes exist for other fibrinogen concentrates (e.g., RiaSTAP); Fesilty is a distinct recombinant product — payers may require the specific NDC on the claim to confirm the correct product was dispensed.
• Prior authorization is typically required: Most payers, including Medicare Advantage plans, will require documentation of congenital fibrinogen deficiency (ICD-10 D68.2) and may not cover this for acquired fibrinogen deficiencies; verify coverage policy before administration.