By being aggressive, it also helps me delay starting the SEPP... assuming the market is kind.
I think you're shooting yourself in the foot.
Your out of pocket for your premium will be *exactly* the same if you estimate higher than actual. The only difference will be that the additional subsidy will come to you at tax time rather than throughout the year in subsidized premiums.
In addition, you're losing out on CSRs (see below), and you're also losing out on taking advantage of the repayment caps (line 28 form 8962). And you're also losing out on the ability to use tax credits to offset subsidy repayments; those tax credits could otherwise go to waste in certain circumstances. Oh, and your cash flow is also worse because of the delay in getting your additional subsidies.
The only benefit I can see is that it might help you avoid underpayment penalties, but I'm not even sure if that's the case (estimated taxes and the rules there are complicated).
Right, I was thinking more of the deductibles and OOP maximums. At $25k MAGI, my deductible is $1k/year. At $30k, it's $9k. So in a year I consumed a large amount of HC, I might keep my income at $25k, otherwise sell some stocks at the end of the year (which I'll have to do eventually) and bump up my income. I'm not sure what's "cheating" and what isn't. Thanks.
You're probably seeing the effect of CSRs. I believe, but am not sure, that if you estimate low and get CSRs, then update your estimate during the year higher, you could worsen or lose your CSRs. If you estimate low enough to get CSRs and then don't update and your income ends up higher, the CSRs are not reconciled and you just get the benefit of those lower deductibles. This is a "loophole" that I'm sure Congress knows about but hasn't addressed.
From the tax law, the only "cheating" I can see is the part in the Form 8962 instructions about "reckless disregard for the facts":
"You, with intentional or reckless disregard for the facts, provided incorrect information to a Marketplace for the year of coverage. See Pub. 974 for more information."
The penalty for which seems to be loss of PTC for that tax year.
(There is, of course, the penalties for perjury for lying on a tax return, but that's not what you're describing.)
Beyond that, I think it's between you and your conscience as to what extent you follow the "intent of the law" and how you feel about taking advantage of the rules.