Yes, some minor changes were made on January 1, in anticipation of the new CAD system coming online mid-year.
The new system is pretty easy to follow. It's a 3-digit system, where:
1st number - indicates an ambulance
2nd number - indicates the station it's running from
3rd number - indicates first out, second out, third out unit
111, 112, 121, and 141 will be the units heard most often.