Log into your online MyVerizon account
Scroll toward the middle of the screen and click on 'more actions'
Under 'device', click on 'phone details'
All the phones on your plan should be listed across the top; choose which phone you are interested in (remember that each has its own contract end date, assuming you have more than one phone on your account)
Click on 'view contract end date' (in blue)
A pop-up screen will show the contract end date for that phone