Can I deduct losses from IRA and 401(k) distributions?

[aliceand]

I'm not yet taking RMDs but am curious if I take a $12,000 distribution, can I deduct losses?  I'm looking to sell some of my losers.

[fanfare]

your investment activity (gains and losses) in an IRA or 401k are invisible to the IRS. Only the distribution matters and that is ordinary income.
If you want to do tax harvesting in the future,  invest the $12,000 into a regular brokerage account.

[Rainman12]

No. You can't take an IRA loss on 'some'; You had to have sold ALL similar IRA accounts to take loss in Basis as an itemized deduction - and even that is not allowed for 2018 returns. Further, it's highly unlikely you have a loss in Basis - ie, value sold at is less than the after-tax amount you contributed.

[dmertz]

The new tax law has eliminated this potential deduction for tax years 2018 through 2025.

[SweetieJean]

OP also asked about 401(k) losses.

[Rainman12]

"Since the money you've invested in your 401(k) hasn't been taxed yet, you can't get a tax break on losses in your 401(k) no matter how much your 401(k)'s value drops."