Deductions & credits

each year you make a non-deductible contribution your basis grows by that amount. See Form 8606 Line 14.

If your latest Form 8606 and/or prior forms 8606 have the wrong amount on Line 14, you have to amend your return(s) to correct that.

 

You don't need an accountant unless you want to pay them to amend for you.

 

@cmancero