Question: We're having trouble with our appeals and redetermination requests, which seem to disappear into a black hole when we send it to our MAC. What could be the problem? Kentucky Subscriber Answer: Many things can go wrong with redetermination requests, so it's hard to know. However, a couple of common errors could be the source of your trouble. Time: You can't wait too long to file an appeal request. Based on the date of the Medicare Remittance Advice (RA) that details the initial claim denial, you have 120 days to file the request. Place: Sometimes people just inadvertently send the appeal to the wrong place. If you're mailing an appeal, you need to review the RA carefully. You'll find both the name of the contractor and the correct address for forwarding your appeal. If you can file electronically through a link on the MAC's website, you can also circumvent the problem of sending the appeal to the wrong address. Remember: You don't send second-round appeals directly to your MAC. Instead, you'll need to send those directly to the Qualified Independent Contractor (QIC) named in your appeals letter.