IVIG and immunoglobulin denials
Intravenous and subcutaneous immunoglobulin (IVIG, SCIG) is expensive, infused repeatedly, and reviewed against a short list of accepted diagnoses. Denials say 'not medically necessary' or 'experimental' for the specific condition, or move the drug to a different benefit or site of care.
The rule that controls this: Plans compare the diagnosis to their immunoglobulin policy, which typically lists FDA-labeled indications (primary immunodeficiency, immune thrombocytopenia, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, Kawasaki disease, and others) and selected off-label uses supported by published evidence. Medicare Part B covers immunoglobulin for primary immunodeficiency at home under 42 CFR 410.10 and the home IVIG benefit; other indications follow local coverage determinations in the Medicare Coverage Database. Plan criteria must be disclosed on request (29 CFR 2560.503-1(m)(8); 45 CFR 147.136).
Last reviewed 13 September 2026 · General information, not legal or medical advice · Apellica is not a law firm
What gets denied
- IVIG for CIDP, myasthenia gravis, dermatomyositis, or autoimmune encephalitis
- Continuation after the initial authorization period when response is not documented
- Dose or frequency above the policy's stated range
- Site-of-care changes: hospital outpatient infusion moved to home or a standalone center
- Subcutaneous immunoglobulin when the plan prefers intravenous
Common denial reasons
- Diagnosis not on the plan's list of covered indications
- Required baseline labs (immunoglobulin levels, vaccine response, nerve conduction studies) not in the record
- No documented failure of first-line therapy where the policy requires it
- Response to prior IVIG cycles not documented in measurable terms
- Plan classifies the use as experimental or investigational
How we approach the appeal
Request the plan's immunoglobulin policy and the reviewer's specialty. Have the treating specialist write to each criterion: diagnosis with supporting labs or electrodiagnostic studies, prior therapies and results, measurable response to IVIG, and dosing rationale. For off-label uses, attach the guideline or peer-reviewed evidence the specialist relies on and identify it accurately. If the denial is 'experimental', the external review process specifically covers that determination (45 CFR 147.136(d)).
Ongoing infusions make most IVIG appeals urgent: request expedited review and expect a decision within 72 hours (29 CFR 2560.503-1(f)(2)(i); 42 CFR 422.584 for Medicare Advantage). Internal appeal filing window: at least 180 days for commercial and employer plans; 65 days for Medicare Advantage; 60 days for Part D redetermination (42 CFR 423.582). External review must be requested within 4 months of the final internal denial for ACA-covered plans.
Immunoglobulin is among the most expensive recurring therapies; a denied course commonly represents thousands of dollars per infusion in billed charges.
- · The denial letter naming the criterion or policy applied
- · Specialist's notes with diagnosis, labs, and electrodiagnostic or imaging results
- · Record of prior therapies and outcomes
- · Infusion records showing dose, frequency, and documented response
- · The plan's immunoglobulin policy (request it in writing)
IVIG and immunoglobulin denial? Let's appeal it.
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IVIG denials by insurer
What each plan tends to cite, and the rule that controls it.
This page provides general information about appeal strategy. It is not legal advice. Outcomes depend on documentation, plan terms, and timing.