A system and method for communicating with contactless IC cards of multiple protocols and power levels includes generating a first alternating magnetic field with an interrogator for energizing a proximate IC card and receiving a data transmission from the IC card. A processor of the interrogator is configured to decode the received data transmission. The interrogator then generates a second alternating magnetic field having a different magnetic field strength than the first alternating magnetic field when failing to decode the data transmission being received from the IC card. The processor then attempts to decode a data transmission received from the IC card in response to the second alternating magnetic field.