What do they mean by nondeductible contributions? I have a few 5498 forms.

[KittyM · Accepted solution]

"Nondeductible contributions" (generally to an IRA) are those which were made with after tax dollars. These contributions are rare, as most people only contribute to their IRA up to the deductible limit for IRA's - $5,500 ($6,500 if over 50) in 2018.  If you contribute more than these limits, it is nondeductible and must be tracked separately for income tax purposes.