If you want to pay more this year, check the box to NOT split the distribution.
Lines 15, 16 and 17 would then be $22,723 (your total distribution)
If your repayment was $15,000 (line 18), then line 19 is $22,723 - $15,000 = $7,723
Meaning, you would owe tax on $7,723.
If you wanted to pay tax on the $22,723, you should not have repaid the loan and in which case, you would not even need the 8915-E.
I'm not tax certified but if you really do want to pay tax on the $22,723, you MAY be able to consider the $15k a non deductible IRA contribution? I think the ability to do that depends on your MAGI.
IF you can do that, you don't need the 8915-E because you would not be taking advantage of the program (which is geared to keep more money in your pocket THIS year).
