Get your taxes done using TurboTax

@kchiles 

We just don't/can't know that...maybe some penalty or interest...maybe none at all.

The way the interest/penalty on underpayment works, if your income is low enough, or regular withholding (but not estimated tax payments) is high enough to cover the expected taxes by the end of the year, then the late estimated payment is not a problem.  AND even when there is a penalty/interest, a bunch of other handwaving can get involved if you decide to not use the default calculations, and instead run thru all the "Annualized Income" calculations when you file next year .

BUT

.....if you are only paying taxes thru quarterly estimated tax payments, with absolutely no tax withholding on your income during the year, then there may be some penalty/interest for paying that first one late.

The best procedure it to have any pension provider, start doing Federal tax withholding at a level where you won't owe any more when you file next year (using the total withholding alone).  State withholding too if you are in an income-taxing state.  (And Federal withholding for SS income too, if you are getting SS income now).

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