Can I buy a new iphone and adjust it to a prepaid plan?

I have the iphone 5s and it sucks, I really want to save up for a new iphone and get onto another prepaid plan. Right now I only pay 40 a month. Would it be easy to do?

If by "adjust" you mean stick in a prepaid SIM card, then yea.

That's how I use my iPhones. Buy them from Apple, stick in my prepaid SIM, done.

Yes