Is $45.75/month in Apple iPhone 8 Upgrade Program only for device itself? And I have to pay additional monthly plan for carrier, right?

What is the cheapest plan among AT and T/ Verizon/ sprint/ tmobile if I need a new iphone 8?

But a phone outright from any vendor you wish, and pay it off by your credit card, or in full. Get it unlocked. Go to Consumer Cellular for your service. Costs me $25 a month for unlimited tag and text and 1G of data. Service is great! I added my husband to share this with me for another $15 a month.