Disagree. I agree with the scenario of having investments in each of the 3 varied accounts.....taxable; tax deferred ; and tax free and then withdraw from the one that gives the most tax efficient result.
One reason we want to have some money in a Trad IRA and not convert all of it is we may find ourselves with high medical expenses later in life and need money for nursing home / assisted living expenses. Assuming ( and I know it is an assumption) that one will still be able to deduct medical/dental expenses on Sch. A of a tax return; one could offset taxes due on Trad IRA withdrawals with these medical expenses. Especially as these expenses will be astronomical in future years.
Maybe that will work out, maybe not. You may never need LTC, so you're just stuck with RMDs on top of SS, perhaps a pension, and whatever other income you have. And if it matters to you, your heirs will have to drain (and pay taxes on) the IRA within 10 years, quite possibly in what may be their highest income years.
Even if you do need LTC, that probably won't come until years after age 72, so you've got RMDs for a number of years until you have the medical expenses to deduct from your income. I would model this to see if it's worthwhile to hold back tax deferred money vs converting at a lower rate earlier. This may improve if the RMD date moves out to 75 as has been considered.
My plan, if I need LTC later in life, is to sell my holdings with high capital gains to use the medical expense deduction. Others may not have enough in taxable to use this strategy, so I'm not claiming this is the best way for everyone.
I think the potential for LTC expenses is a
factor in Roth conversions, not a hard requirement to leave some in the tIRA. Suppose I could convert all of my tIRA at 0%; I would rather do that and have all that money in a Roth rather than leaving some in a tIRA for the LTC case. This is my point. Leaving some in a tIRA should not be a goal in of itself, but it might very well be the outcome of the best strategy.
Another factor for leaving money in a tIRA is charitable giving, through QCDs and/or through your estate. But again, if I can convert for free, I would do so and donate appreciated stocks from taxable instead. The likelihood is that I can't convert all with 0% taxes, so the outcome of the best strategy is probably leaving some in the tIRA for giving.
Now that I've hopefully convinced you that fully converting your Roth at 0% would be better than leaving some to write off LTC expenses, it follows that fully converting at a relatively low tax rate
might be a better strategy than leaving some in the tIRA for those expenses. It's worth running some numbers to see which works best.
And by the way, you don't get to deduct medical expenses dollar-for-dollar against taxable income. The first 7.5% of income is excluded from the deduction. The more income you add, the more expenses are excluded. Factor this in too.
