I would suggest keeping the 5498 if you took any deduction for the tax
year (even if the contribution wasn't made to the account the 5498
applies to). I would also suggest keeping the 5498 if there is a
Required Minimum Distribution during the next tax year.
Note: I quit asking the "Do I have to keep a copy of this?" question
after I started keeping all my tax records in digital form years ago.
Storage is so cheap the time and effort spent determining the correct
records retention policy for each document seemed like a waste of time.