Health insurance marketplace; How to report income???

[Holyoak]

Since I am a 49 y/o retiree, with no W2 income, just what my investments yield, I'm not sure what to put in the box that asks for income.  Obviously it fluctuates by the whims of the market, and I don't want to miss out on credits by over stating, but also don't want to under report either. 

How do you folks come to the correct number for income?  Do you simply use last years tax returns AGI?  Also, what happens if say you report $32,000 as income, receive a tax credit, but when you file your income is $38k, because the market smiled upon you?  Do you pay some kind of penalty, along with repayment of any tax credit?  Same if the market takes a tumble, and your income is say $28k when you file, do you get a refund?  Thanks for taking time to read, and reply to my questions.

[secondcor521]

I retired in February this year.  I did not use last year's AGI because my situation has obviously changed.

For income from work, I just used the information from my last paycheck to figure out what will be on my W2 this next January (basically gross income - pretax deductions + taxable life insurance premium benefit).

For dividends and other things that vary with the market, I just assumed that I would receive the same amount this year as I did last year.  I used the numbers directly off of my 1099-DIVs from 2015 to estimate income for 2016.

I am planning on a Roth pipeline and just estimated what my taxable conversion will need to be to keep my pipeline going (basically what I plan to spend in 2021).

Regarding your last several questions, it works similarly to regular income tax withholding.  You estimate your income for 2016, then when you go to file next April, you will report your actual income.  If your income was higher than you predicted, then your ACA credit will end up being lower than you actually received, so you will have the amount you have to pay back added to your income tax owed (or you will receive a smaller refund).  If your income was lower than you predicted, then your ACA credit will end up being higher than you actually received, so you will receive the additional ACA amount in addition to your refund (or the additional ACA amount will reduce the amount you owe).  This reconciliation is done on IRS Form 8962.

There are some asterisks and caveats to these generalities.  If you receive CSR through the ACA and you shouldn't have, you don't have to pay that back.  There are certain limits on how much of the ACA credit you have to pay back.  There may be others; I am not an expert.

If your state marketplace doesn't believe your estimate, then they can ask you to justify it.  Then you get to write them a letter of explanation.  I think they can adjust downward or refuse to give you the advance monthly credit if they don't believe you.  In my case, I estimated a much lower AGI, they asked for an explanation, I sent them a letter, and I haven't heard a peep from them since and I'm still getting the advance monthly credit.

[Holyoak]

Thanks a lot secondcor521, very helpful reply!  Appreciate it, and have a nice weekend.

[BTDretire]

Since I am a 49 y/o retiree, with no W2 income, just what my investments yield, I'm not sure what to put in the box that asks for income.  Obviously it fluctuates by the whims of the market, and I don't want to miss out on credits by over stating, but also don't want to under report either. 

How do you folks come to the correct number for income?  Do you simply use last years tax returns AGI?  Also, what happens if say you report $32,000 as income, receive a tax credit, but when you file your income is $38k, because the market smiled upon you?  Do you pay some kind of penalty, along with repayment of any tax credit?  Same if the market takes a tumble, and your income is say $28k when you file, do you get a refund?  Thanks for taking time to read, and reply to my questions.

The ACA uses MAGI to calculate the subsidy. MAGI is AGI with several deductions added back in.
See this page.
https://www.irs.gov/businesses/small-businesses-self-employed/passive-activity-loss-atg-exhibit-2-2-modified-adjusted-gross-income-computation