what is the lifetime if an Arris NVG 589 modem/router

There are models that have reached EOL (End Of Life) that are still working in the field... these include the 510, 3600, 3800, 3801, 3812 (iNID, first bonded pair gateway 2011-2013), 5031.

They are replaced as encountered on a service call to a current model which include the 210, 589, 599, 5268. Note that the 589 is still a model being provided to customers on installation or repairs as required. 

If your experiencing an issue could call and request a replacement model be direct shipped to you, you exchange and return the original model to ATT via FEDEX or UPS.

Do you have UVERSE IPTV service? If yes, does any of the receivers connect using coax? If yes only the 589, 599 or 5268 gateways can be used. 

Thank you for your response. I am trying to prepare for the techs visit and not get too (Edited per community guidelines) when he informs me of a re-curring monthly bill for $7.  Shouldn't cost anything extra.  

We will see what happens tomorrow.

The tech may or may not inform you since their job is to install.