Generally, credit card issuers don't care where you live, as long as you're continuing to make your payments. I left the country for a year and a half, didn't tell my bank I was going anywhere, and had no problems. I am acquainted with a number of people who spend significant time out of the country who still hold US credit cards. They just continue paying on them.The question: how can I make arrangements for this? After I leave the country, is it possible for me to keep my credit card and bank account active, or do I have to "forfeit"/default on them automatically if I no longer live in the country?
As Mr. K notes, the USCIS does not check your credit, so you're not going to have difficulties leaving the country.

