First, be aware that many posts have incorrect dates because they were mass-transferred to new board software, and may have been several years old at the time.
If you are a W-2 minister, you have tax assessed in two places, income tax on line 7 of form 1040 for your W-2 box 1 wages, and schedule SE for your (wages+housing). Before tax reform, you could deduct work expenses from your taxable income subject to income tax using form 2106 as a misc itemized deduction subject to the 2% rule. These work expenses were also subject to the Deason rule of course. Separately, I have told people that they can reduce their income subject to SE tax by adjusting schedule SE to reflect those same business expenses. They were not subject to the 2% rule but I always treated them as subject to the Deason rule. Post tax-reform, the itemized deduction for W-2 employee expenses is disallowed but ministers can still deduct work related expenses from Schedule SE. .
As a 1099/Schedule C minister, by making the Deason adjustment to schedule C instead of schedule SE, you are already deducting your work expenses from both your income subject to income tax and your income subject to SE tax.
By adding the Deason adjustment back to schedule SE, you would be reducing your expenses according to the Deason rule for your income tax, but taking the full expense deduction on your SE tax. I've never heard of that before and if there is some nuance in the Deason court ruling, I am unaware of it. I see your accountant's explanation but I don't know if it's true.
This is one of my main resources.
https://www.ecfa.org/PDF/MinTax_Preparing_2019.pdf
It's up to you of course, if you want to apply the thinking from your 2009 accountant. I couldn't confirm or refute it without much more research than you are paying me to do 🙂
