DH filed 1040 but didn't file 1099 even though our investments advisor sent us the info. What to do?

Answer 1

You have two choices.

1) file an amended form 1040X including all your income, and pay the additional taxes

2) wait for a letter from the IRS sending you a bill for the additional amount, plus interest and penalties.

And the letter WILL come if you don't file the amendment. It might take several months or over a year, and by that time the interest and penalties will have added up.

What was he thinking? Or maybe he just wasn't.

Answer 2

You need to file a 1040X - amended return. It needs to be filed by April 17 to avoid possible penalties.