We just had the doctor sign the Igenex form and paid for the testing with our credit card (listed on form). Then when Igenex finished the testing they sent us a detailed receipt to submit to insurance for reimbursement. Our insurance reimbursed us 70% in the past and just recently covered 90%. Our insurance does not require a medical letter of necessity.
Note- when submitting form to insurance, be sure to circle the comment of using the modifier code. Our insurance never applies it, and covers the IgM/IgG as one test (since they have the same cpt code). I always have to call them to get the rest reimbursed.