Covered without prior authorization (high confidence)
Documentation Required
Laboratory evidence to support diagnosis of B-12 deficiency: serum cobalamin (vitamin B-12) measurement, with interpretation guidance (appendix): >300 pg/mL (>241 pmol/L) = normal; 200–300 pg/mL (148–241 pmol/L) = borderline; <200 pg/mL (<148 pmol/L) = low/consistent with deficiency.
Recommended diagnostic tests in suspected deficiency: CBC, blood film, and serum cobalamin.
Consideration of functional markers in borderline/uncertain cases: methylmalonic acid (MMA) and homocysteine (Hcy) (MMA and Hcy are increased in B-12 deficiency); measurement of MMA and/or Hcy may be recommended for borderline serum B-12 results.
Holo-transcobalamin (holoTC) may be used as an early marker in certain settings but is not reliable in patients with renal dysfunction; documentation of renal function if holoTC used.
Key Coverage Criteria
Macrocytic anemia
Documented cobalamin (vitamin B-12) deficiency (clinical and/or laboratory evidence such as low serum B-12 and/or elevated MMA/Hcy) requiring replacement therapy.
Pernicious anemia (decreased production or action of intrinsic factor) causing vitamin B-12 deficiency.
Post-gastrectomy vitamin B-12 deficiency (loss of intrinsic factor production).
Blind loop syndrome / bacterial overgrowth resulting in competition for vitamin B-12 and causing deficiency.
Surgical resection of the ileum resulting in loss of the site of vitamin B-12 absorption.
Clinical documentation of signs/symptoms (e.g., megaloblastic anemia, neurologic deficits such as paresthesias, ataxia, sensory loss, mood/cognitive changes) to support medical necessity for parenteral therapy, especially when parenteral therapy is chosen over oral therapy.
For pemetrexed patients: documentation of pemetrexed administration and timing to justify the required B-12 injections (1,000 µg IM within the week before first dose and every 3 cycles thereafter).