Using it for emergency service, our county uses analog but our mutual aid company in neighboring county uses digital.
What type of digital are they using?
Is it digital trunked?
There are a few different types of digital that are used in public safety systems, P25, NXDN, DMR, etc. They are not interchangeable, so you need to know which one they are using.
Also, digital makes it really easy for them to use encryption, access controls, etc. so before you spend your hard earned money on a digital radio, be sure you'll be able to use it on their system. If they are running encryption or any sort of access control, you won't be able to use your radio on their system without them letting you.
And, as always, if you are going to use your radio on another agencies radio system, you MUST (FCC rules) have written approval from the license holder of the other system. They are the ones that are responsible for the operation of their radio system, and someone else adding radios isn't OK. There is no exception to this rule for public safety agencies, volunteers, hobbyists, etc.