Even if you have super low income and you are on the border for benefits (EITC, Medicare), donating to a charity will not make you eligible for those benefits because that eligibility is determined by AGI, which is income before deductions.

The only situation which this makes sense on net is if you tell your tax advisor that you want to donate some amount of money over the next few years. Then the advisor might tell you to donate in high-earning years to offset a higher marginal rate. In the above proposed scheme, the IRS would only get one year's worth of data, so it cannot recommend you this type of tax avoidance.

If you bunch deductions, you might alternate between the standard deduction and itemizing deductions, meaning if you want to support charities with $10K per year, you're better off to donate in Jan and Dec of the same year (itemizing), then skip 13 months (taking the standard deduction), then donate twice in the year after that (itemizing), etc. With the increased standard deduction, this may be needed to allow your donations to become deductible at all.

There are other planning strategies that a combined advisor and preparer can help with. (Using your HSA optimally as a retirement account. Optimizing your Roth conversions over the years. Modeling whether Backdoor Roth contributions make sense (or "what would you have to believe is true to have them make sense?") For business owners, setting the balance between your salary and distributions of profits.) Those are advice activities that overlap with a detailed understanding of your financial and tax situation and often mean that you have to change something about the structure or timing of your activity to accomplish your goal.

The IRS is in an OK position to look back and judge "based on what actually happened, here's what you owe", but in a terrible position to offer optimization advice.

Wait, can you explain how tax brackets work because I think there may be a fundamental misunderstanding here.

If we have two brackets, 10% for <=$100 and 90% for >$100, what do you think the tax bill would be for someone who earned $101?

$10 for the first bracket. The remaining untaxed income is $1, taxed at 90% = $0.90 tax.

But the Republican Party has spent a lot of money to make people think that the tax would be $90.90 (i.e,. a flat rate), which is why so many people are opposed to increasing the tax bracket rates...even though the actual affect is marginal to most people (even those affected).

I feel like every April news orgs should just run segments with accountants doing this example.

For example, if you fill out your form by hand and say that you owe X, using the single-filer rates but you're married and should have used the married-filer rates, the IRS will notice your error when they process your return and send you a refund check for the difference.

A tax advisor will advise you to possibly make a donation...if it makes sense to do so (i.e., if you itemize). Because you're specifically paying them a lot of money to minimize the amount of tax that you owe.