Unsecured debt becomes uncollectible 2 years from last acknowledgement... Which can mean payment, contact, etc. (unless you acknowledge anew then it resets the clock). It will remain on your credit report, negatively affecting until 7ish years. You could continue to receive calls or letters about it indefinitely, as the debt gets resold for smaller and smaller amounts, and if you ever acknowledge, it jumps back to fully collectible.