Roth IRA Contribution question

[VAer]

https://investor.vanguard.com/ira/roth-ira-income-limits 

As the link indicates, when income goes above a certain limit, it is not allowed to contribute to roth IRA.

The question is: how should people know his/her current year's income (if income varies throughout the year)?

Example: John is single, his salary (W2) income is less than $124K, and he contributes $6000 roth IRA in July 2020. Then in September 2020, he sells his stock and makes more than $200k capital gain, and his 2020 income is way too high and he is not qualified to contribute any amount to roth IRA. What will happen to earlier contributed $6000 roth IRA?

Thanks.

[MinhT1]

Please read this IRS document for more information.

Your ability to contribute to a Roth IRA may be reduced or eliminated depending on the MAGI for the whole year.

If at th etime of filing your tax return, you find out that you have overcontributed, you should withdraw the excess contribution (plus any earnings thereof) by the due date of your tax return, which this year has been extended to July 15, 2020.

If excess contributions have been withdrawn by that date, no further action is needed on your tax return. Any earnings will be taxable in 2020.

[susan58]

i received 1099 nec for 3000.  Made 6000 roth ira contribution by mistake.  not getting any credit for roth on my 2020 taxes.  First entered directly in 1099 section then read some posts and deleted and ran through the self employment area.  Neither is working to give my partial credit that i am expecting.  How do I get TT to recognize $3000 income as Roth qualified?