You will have to amend your 2020 federal tax return to report the gambling winnings and losses.
See this TurboTax support FAQ for amending a 2020 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-2020-return/L3XdA1Pw8_U...
Gambling winnings are reported on a tax return as ordinary income. Gambling losses are reported as a Miscellaneous Itemized Deduction on Schedule A. You DO NOT subtract your losses from your winnings when reporting your winnings on a tax return.
If the total of all itemized deductions on Schedule A are less than the Standard Deduction for your filing status then Schedule A will not be used for deductions.
Standard deductions for 2020
- Single - $12,400 add $1,650 if age 65 or older
- Married Filing Separately - $12,400 add $1,300 if age 65 or older
- Married Filing Jointly - $24,800 add $1,300 for each spouse age 65 or older
- Head of Household - $18,650 add $1,650 if age 65 or older
To enter, edit or delete Gambling Winnings and Losses -
- Click on Federal Taxes (Personal using Home and Business)
- Click on Wages and Income (Personal Income using Home and Business)
- Click on I'll choose what I work on (if shown)
- Scroll down to Less Common Income
- On Gambling Winnings, click the start or update button
