Since it appears that you did not meet the safe harbor for either 100% (or 110% for those with higher AGI) of your 2022 tax liability or a balance due of less than $1,000 based on the tax payments for 2022 that you did make, you needed to make an estimated tax payment by January 15, 2024 to avoid underpayment for the fourth quarter of 2023. With all of your tax payments entered into TurboTax, TurboTax would have informed you that you would be subject to an underpayment penalty.
Because your income is treated by default as received evenly throughout the year while estimated tax payments are only credited when actually paid, even if you had made an estimated tax payment by January 15, 2024 you would likely need to annualize income on Schedule AI of Form 2210 to avoid a penalty by treating income as received when actually received. The need to prepare Schedule AI can be avoided either by having a sufficient amount withheld for taxes to cover the amount required to meet a safe harbor, (unlike estimated tax payments, tax withholding is treated as having been paid evenly throughout the year) or by making estimated tax payments for each quarter of the year. For example, you could have allocated some of your December 2023 traditional IRA distribution to tax withholding, then within 60 days substituted other funds to complete an indirect conversion to Roth of the portion withheld for taxes. This would have given you until at least late January 2024 to have come up with the funds to complete the conversion as well as avoiding the need to file Schedule AI.
