First, a little sleuthing is necessary. If you filed taxes, you will need to check your most recent return to see which address they have on file. Next, you will want to review the status of your check. You can do that on the Internal Revenue Service’s website via a feature called “ Get My Payment .” It is worth noting that, according to the IRS’ website, the “Get My Payment” feature will not allow you to change your address — it is only for seeing the status of your check. You can also use a free U.S. Postal service feature called “Informed Delivery” which sends you a picture of your mail as it's processed through the post office. This won’t work retroactively, but if there is a chance that your check hasn’t been sent yet, this would be another way of tracking it.