After entering the four MD estimated payments, the total penalty calculated is not right (line 18). 

4th quarter payment, which deadline is on 01/15/25, was paid a bit late on 01/21/2025. 

The interest factor on Form 502UP, line 16, for the 4th period is set to 0.0283% by default. However, according to the MD 502UP instructions, it needs to be modified depending on how late the last payment is. 

In this case, I performed a manual calculation, and the correct interest factor for the 4th period should be 0.0096%.

This formula (1 month late / 12 months x 11.4825% for 2024 tax year) should be taken into account when calculating the 4th period interest factor, but I cannot get the right % on the form. Instead, the full 0.0283% is used, increasing the total underpayment penalty for MD ($400 difference).

I checked on the community and couldn't find this issue mentioned in the past.

I worked together with the Intuit technical support, and the assistant couldn't find a way to fix this issue.

Since I'm a new user, I'm hoping that I missed an entry somewhere, but I tried everything and still couldn't find an answer. 

I know I could override the state underpayment penalty field, BUT that means I need to manually calculate the interest factor and penalty and force the amount on the form. Most of my clients are MD-based, and this is a form that I use all the time and doing it manually will be time-consuming. This should be an easy calculation for a tax professional's preparation software. 

Thanks in advance!