Late but...
What I have noticed in looking at the 502UP prepared by TurboTax is that the expectation is that 25% of your total tax due for the year must be paid with each estimated payment period. In reality, this does not seem to match the IRS income periods of 3 for 4/15, 2 for 6/15, 3 for 9/15 and 4 for 12/15. Which does not represent an even distribution yet MD wants to use one.
It looks like there is an option to record actual income for each period on the 502UP but that does not seem to be the Turbo Tax approach which would then require you to manually update the 502UP. Best thing to do is follow the guidelines for 110% of the previous year or 90 % of the current year (which ever is lower) and then may EQUAL payments over the year (divide the MD tax due by 4).
