Immunosuppressive Drug Coverage Act of 2003

Immunosuppressive Drug Coverage Act of 2003 - Amends title II (Old Age, Survivors and Disability Insurance) (OASDI) of the Social Security Act to: (1) continue entitlement to prescription drugs used in immunosuppressive therapy furnished to an individual who receives a kidney transplant for which payment is made under Medicare; and (2) extend Medicare secondary payer requirements for end stage renal disease beneficiaries.Amends the Public Health Service Act, the Employee Retirement Income Security Act of 1974, and the Internal Revenue Code to set forth requirements for group health plans to provide coverage of immunosuppressive drugs.