We need to know what kind of scanner you have: If its a Radio Shack PRO-96, or a Uniden Bearcat BC-296D/BC796D, then you should be able to listen to most digital systems with no issues. If its a BC250D/BC785D, then you will need the digital card. Just so you know: If your trying to monitor a EDACS Provoice system, you can hang up listening to any of the Provoice digital TG's, as there is not and will never be a scanner that can monitor provoice digital.
We also would need to know What State you are talking about?