what specific documents get mailed with form 8453 for form 8949?

[ksmoot01]

I have form 8949 box H checked and form 8949 box I checked and form 8949 box K checked and form 8949 box L checked...but I don't know what else I'm supposed to send in with these forms...do you know?

[pk]

@ksmoot01 , while this whole 1099-DA is new as also check boxes H etc. that you are using, as I understand  form 8453 is required only when you do not report electronically line by line-- i.e. choose to report summary.   Here is something from the Instructions for  form 8949 --  2025 Instructions for Form 8949

"E-file. If you e-file your return but choose not to report each
transaction on a separate row on the electronic return, you must
attach Form 8949 to Form 8453 (or the appropriate form in the
Form 8453 series) and mail the forms to the IRS. (However, you
can't attach a paper Form 8949 to Form 8453-FE.) You can
attach one or more statements containing all the same
information as Form 8949, instead of attaching Form 8949, if the
statements are in a format similar to Form 8949. "

Please see the instruction for the form 8949 to see if you really need to send in form 8453 with detail attachment showing back-up information.

Hope this helps