There is an annual form that's sent to farmers and it is required by Federal Law.
If you have any questions about what you received call the your local Farm Service Agency office (usually found in or near post offices in rural communities). They can identify the form and, if it's real, give you the 5Ws about it.
If you can't find the FSA office call your local County Extenstion Agent. They willl get you the information you need or tell you how to find it.