Get Paid for Immunization Claims March 16, 2018 Starting May 1, 2018, IHN-CCO will begin denying all claim lines billed with administration codes for immunization services. To ensure you get paid for immunizations, please follow the Oregon Medicaid Immunization Administration Fee Process of billing with the appropriate vaccine CPT/HCPC and modifier SL or 26. Each claim line billed with the appropriate CPT/HCPC and modifier will be reimbursed at $21.96. For more information, review our updated Reimbursement Guidelines for Childhood Immunizations.