Money in brokerage account counted towards AGI?

[DK903]

I am receiving conflicting answers in regards to putting some of my income in a brokerage account.

1. Hypothetically if my total income is $100,000 and I put $30,000 into a brokerage account do I pay federal taxes on the original $100,000 or do I pay taxes based on $70,000? 

[parleyvernon]

On a normal brokerage account, you pay taxes on the 100k of income.  Any additional realized gains (sell of a stock) or dividends will create additional taxes on those.  

If you put the money in a tradional IRA, you would be taxed on only 70k.  The rest is taxed when you withdraw it (without penalty after 59.5 years of age).   FYI this is a bad example since you can't put 30k in one year in a tax-advantaged account.  

If you put it in a roth IRA you are taxed on the full 100k and it grows tax free and is never taxed again (assuming you don't touch it until after 59.5.  FYI this is a bad example since you can't put 30k in one year in a tax-advantaged account.  

[Critter-3]

Ok you pay taxes on your taxable income ... period  And  what you do with that income once you pay taxes on it is immaterial.  So you could put under the mattress, in a savings account or invest it in the market or cds  thru a broker's account or bank account.  

Now to reduce your taxable income you could put it into a retirement account of some kind ... maybe an IRA  or 401K or something else that is either deductible either on your tax return as an adjustment or at work as a pre-tax contribution.   

[Opus 17]

If you can put your income in a tax-deferred qualified retirement account (401k, 403b, IRA) then it is not taxed when contributed, but is taxed on withdrawal in retirement.

Other than that, all your income is taxable, and how you invest it later doesn't matter.  With a traditional brokerage account, you will also pay taxes on dividends and capital gains each year, but not when you withdraw your original contributions.  (In other words, suppose you invest $30,000 from your after-tax income, and in one year the account pays $500 of dividends and increases in value to $35,000, and then you withdraw it.  You would pay income tax on the dividends and capital gains tax on the $5000 increased value.)

[fanfare]

you will pay tax on what's in your brokerage account if Elizabeth Warren gets her way.