A method and apparatus for managing ATM formatted MPEG SI data in a television set-top box. A virtual channel indicator (VCI) is used to associate a segment of SI data with a virtual channel. An ATM processor receives a stream of ATM packets containing SI data from an out-of-band tuner. The ATM packets include the VCI in a header thereof. The ATM processor stores the SI data in a buffer memory associated with the VCI for retrieval by the ATM processor at the request of the STB system processor.