I'm a tax accountant.

You'll never make less due to income tax for making more money.

You can start to get certain credits phased out and can become subject to things like the Medicare surcharge.

But it's still unlikely that making more will ever get you less.

In a similar track though, I refused raises for a couple years because my kid was in college. If I got a raise, I would be kicked into the next income tier of financial aid eligibility, and that could've been catastrophic. Those lines don't seem to phase as much as they seem to be hard cutoffs - at least as far as my kid's specific school was concerned. All of her financial aid (grants, not loans) came directly from the school, not the government.

I also was able to enjoy a little bit of education expense credit on my tax return because if it, but that part was nominal.

The biggest hit has been going from head of household with a dependent tax credit to single with fuck all credits. Fortunately, I can itemize my way into a deduction midway between single and head of household, so I got that going for me, which is nice.

Edit: Wow, that was a gibberish filled gummy induced wall of text. Nothing particularly factually incorrect, but man what a slew of non sequitur.