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Winter 2020 - Integrated Care

A Guide to Immune Globulin Billing and Reimbursement

These guidelines are intended to assist providers in following proper procedures and submitting required documentation to ensure payment for IG therapy.

by Abbie Cornett, Michelle Greer, RN, Ronale Tucker Rhodes, MS, and Leslie J. Vaughan, RPh


GETTING REIMBURSED for expensive immune globulin (IG) therapies can be challenging and frustrating for providers for a couple of reasons. First, what is required when submitting a claim may vary depending on the insurer. Second, denial often occurs due to lack of pre-authorization and incomplete and/or inaccurate claims submission requirements. Following is a guide to assist providers to ensure they are reimbursed for the cost of these medications.

When Is IG Treatment Covered?

IG is approved by the U.S. Food and Drug Administration (FDA) to treat primary immunodeficiency diseases (PIs), immunemediated thrombocytopenia purpura, Kawasaki disease, chronic lymphocytic leukemia, chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy. However, many other diagnosed indications not FDA-approved for IG therapy may also be reimbursable.

To determine whether the cost of IG therapy will be reimbursed, providers administering the therapy should conduct a thorough benefits investigation for a patient prior to initiating therapy. This investigation will reveal whether the payer requires a patient to use a preferred provider, whether pre-authorization is necessary and whether IG therapy falls under the patient’s prescription benefit or major medical benefit. In addition, it will reveal the patient’s deductible under the major medical benefit and how much has been satisfied, the maximum patient responsibility and how much has been satisfied, what the plan pays (percentage) and the site-of-care (which may include the patient’s home, the physician’s office or a hospital outpatient infusion suite) and in-network options. Once the benefits investigation is complete, providers will be informed about their options before moving forward with the therapy.

Obtaining Pre-Authorization

Years ago, pre-authorization for IG therapy was not routinely required, but today it is generally required by most commercial payers and by Medicare Part D plans. Once authorization has been given by a payer, treatment can begin. Typically, pre-authorization is obtained by providers based on information provided by the prescriber.

Prior authorization and insurance coverage for IG vary based on the patient diagnosis, where the patient will be infused, who will be submitting claims for the infusion and by the type of payer source. There are many differences between commercial insurance and Medicare. For example, commercial insurance companies typically will reimburse for IG to treat many disease states regardless of whether they are designated as FDA-approved. On the other hand, Medicare Part B will reimburse IG for most diagnosis codes in the physician office or hospital outpatient setting. But in the homecare setting, Medicare Part B reimburses for only 24 specific diagnosis codes (which is new since prior to August 2019, Medicare B reimbursed for only 14 diagnosis codes at home). Also, Medicare Part D may reimburse for additional diagnosis codes in the home (Table 1).


Table of Medicare B Diagnosis Codes Covered at Home


When obtaining pre-authorization, providers must accurately report a patient’s diagnosis, symptom or complaint codes to the highest level of specificity. In addition, all diagnoses generally must be substantiated through clinical and diagnostic documentation. This may include office notes and/or a history and physical, lab work, procedures performed during the work-up, and any medications tried and failed, not tolerated or contraindicated. In addition, results of any prior response to IG therapy should be provided if applicable.

The No. 1 reason for delaying an authorization is incomplete clinical information from the prescriber. Clinical information for PI patients should include the history of infections (type, treatment, occurrence), Ig levels (IgG and subclasses IgM and IgA), vaccination response (failure to show a response to pneumococcal, tetanus and diphtheria vaccines) and other tests depending on the type of immune deficiency.

For neuromuscular diagnoses, results of tests such as a nerve conduction, electromyogram (EMG), muscle biopsy and spinal tap may be required. For example, for CIDP patients, documentation required to approve IG may include an EMG, nerve conduction studies, cerebral spinal fluid tests and a history of symptoms, as well as a complete neurological examination.

Every payer, whether private or government, has different guidelines for approving IG. Some are very simple, and others are very detailed. If it is determined the diagnosis is within a payer’s guidelines and proof of that diagnosis is submitted, IG should be approved.

Billing for Reimbursement

Billing codes for reimbursement are the responsibility and liability of the providers of IG therapy, including the drug, supplies and nursing costs (if applicable). Codes should include, but are not limited to, national drug codes, ICD-10-CM codes and Healthcare Common Procedure Coding System codes.

For a Medicare patient infusing IG in the home, nursing is 100 percent covered under Medicare Part A when the nursing is provided by a Medicare-certified home health agency if the physician certifies the patient is homebound. If a patient is not deemed homebound, the cost for a nurse to visit the home may be billed to the patient. However, on Jan. 10, 2013, the Medicare IVIG Access Act was enacted, which provided for a demonstration project to examine the benefits of providing coverage and payment for items and services necessary to administer intravenous IG (IVIG) in the home for PI patients. In addition, as a result of the 21st Century Cures Act, there is now coverage when a nurse is in the home to administer subcutaneous IG via a pump. This coverage for nursing is limited to the 24 diagnosis codes covered by Medicare Part B.

Because the duration of authorization differs from payer to payer, deadlines for obtaining authorizations and for billing must be adhered to. Prior to pre-authorization, the payer may require evidence of a positive response to IG, which may be documented in the form of an exam performed by the physician or by lab work. If deadlines are met and the proper billing procedures are used, IG therapy should be reimbursed without issues. Some manufacturers have coding guides or reimbursement staff to assist with billing codes (Table 2).


Table with manufacturer contacts for billing assistance

Filing an Appeal

There is always a chance authorization may not be granted for IG. When a payer denies authorization for IG therapy, the prescriber will receive a letter stating the denial and the reason. If this happens, an appeal can be made. Instructions on how to appeal are always included in the denial letter.

The first thing that should be checked prior to filing an appeal is whether the proper codes were submitted on the claim. If they were correct, the provider can appeal by submitting a letter of medical necessity (LMN) or requesting a peer-to-peer review between the prescriber and a medical director from the insurer.

The LMN should state the medical necessity of IG therapy particular to the diagnosis, as well as provide evidence-based medical data that pertain to the physician’s diagnosis. Evidence-based medical data can often be obtained by conducting a search of medical journals that substantiate the effectiveness of IG therapy for a particular disease state. In addition, the LMN should indicate the failure or intolerance of other therapies. And, if there is a prior response to IG therapy, that should be included.

In some cases, rather than a written appeal, a conversation known as a peer-to-peer review may be better, especially for complex cases. In this situation, the prescribing physician and the insurance company’s medical director can discuss the justification for IG therapy. The denial letter provides instructions for requesting a peer-to-peer review.

It’s important to note that under the Affordable Care Act, there are new health insurance appeal rules that apply to health plans created or purchased after March 23, 2010.1 Specifically, when a payer denies payment for a treatment or service, an appeal can be requested, and the payer is required to review its decision. For plan years or policy years beginning on or after July 1, 2011, when the payer denies a claim, it must notify the patient of the reason the claim was denied, the patient’s right to file an internal appeal, the right to request an external review if the internal appeal is unsuccessful, and the availability of a consumer assistance program (if the state in which the patient resides has one).

When an internal appeal is filed, the payer must give a decision within 72 hours after receiving the request when appealing the denial of a claim for urgent care, within 30 days for denials of nonurgent care not yet received, or within 60 days for denials of services already received. If after an internal appeal the payer still denies the request for payment or services, an independent external review by an organization that will decide whether to uphold or overturn the payer’s decision can be requested. If the external review organization overturns the payer’s denial, the payer must reimburse the claim.

The internal appeals rights under the Act take effect when the plan starts a new plan year or policy year on or after Sept. 23, 2010. The external review rights took effect Jan. 1, 2012.

Accuracy and Timing Are Crucial

Patients who rely on IG therapy could be placed at great risk of medical complications should they be denied coverage. With the prohibitively high cost of IG therapy, most patients are unable to afford the drug without coverage. What’s more, when an appeal is necessary, patients, physicians and infusion providers all face financial hardship with time-consuming delays in the appeals process. Therefore, accurate and thorough authorization and error-free billing practices will provide a win-win situation for all when this critical lifesaving therapy is needed.

ABBIE CORNETT is the patient advocate for IG Living magazine. MICHELLE GREER, RN, is senior vice president of sales at Nufactor, a Specialty Infusion Company. RONALE TUCKER RHODES, MS, is the editor of BioSupply Trends Quarterly magazine. LESLIE J. VAUGHAN, RPH, is senior vice president of clinical programs at Nufactor, a Specialty Infusion Company.

Editor’s note: This article has been updated from the original published in the February-March 2013 issue of IG Living magazine.



  1. Appealing Health Plan Decision. Accessed at