Got an overpayment notice, what now? after 6 years as an IT help-desk technician

The agency says I reported earnings incorrectly, but I think I followed the instructions. I did not notice any errors at the time. Are payment plans possible?

I asked for a waiver and a plan in the same call, and they gave me both forms. It was less scary than I expected.

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.