" Does it matter when during the year I do the ROTH conversion"
It matters when you make the Estimated Tax quarterly payments.
If your quarterly withholding and estimates for 2025 are at least 100% / 4 = 25% ( 110% / 4 for certain high income taxpayers) of your 2024 tax, there will be no penalty on your 2025 tax return, regardless of any jump in income.
you are protected from a sudden capital gain or spike in income at year end.
you know your prior year's tax when you file by April 15, which is also the first estimated tax payment due date.
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OR
If you can arrange to meet the "Required Annual Payment"
entirely through withholding , the timing does not matter. ES payments are not needed. There will be no penalty.
This is the default basic rule.
Otherwise, see Form 2210 Schedule AI for how to reduce your penalty.
@Kipmc7
