Just to note: An attached statement means that the tax return cannot be e-filed but must be mailed. Because mailed tax returns are still electronically processed after a data entry clerk manually (or scans) the mailed tax return into the processing system. While the IRS processing system has a place for attached information to be entered, sometimes (often?) it is missed and just stapled to the paper return which is stored.
Also, the check between the 1099-R, your tax return and the 5498 is usually done by an IRS computer that generated a computer generated letter showing the mismatch. Unless a human intervenes and reads the statement then you might still get a letter since most such letters are never seen by a human until you receive it and mail back your response.
If you choose to mail the return and the statement then keep a copy in case the IRS computer still send you a letter in a year or two that there is a mismatch on the 5498 form. If you do, just respond to the letter with the copy.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
