Do you need to dial a 1 in front of the 928?

Yes, when dialing a long-distance number in the United States, you typically need to dial a "1" before the area code, which is 928 in this case. So, if you're calling a number with the 928 area code from outside that area, you would dial 1-928 followed by the local number. If you're calling from within the same area or as part of a local call, you do not need to dial the "1."