If you must report distributions from a variety of retirement plans, investments, and accounts, the IRS has provided a head start by issuing the 2026 instructions for Forms 1099-R and 5498.
Incorrect IRS Forms 1099 are a worry, since Forms 1099 generally saddle you with income you have to report. Of course, if you have income, you must report it, whether or not you receive a Form 1099.