Penalty/Interest on my 2024 Tax Return Summary

[sxchan]

I just finished my 2024 tax return, and the summary page shows an amount for the Penalty/Interest.  I thought the tax return is due 4/15.  Why would I get a Penalty/Interest before the 4/15 deadline?  If I paid my owed taxes before 4/15, I should NOT have any penalty or interest.  Any idea what happens here?

Thanks!

[MaryK4]

To avoid the penalty, you can make estimated payments equal to the safe harbor amount by making four equal timely estimated payments or a payment in the first quarter which is equal to 100 percent of last year's total taxable income multiplied by the current year's rate. To use this safe harbor method, the taxpayer must have filed a full year return in the prior year.

See How does the department calculate the estimated underpayment penalty?