How to handle multiple brokerage accounts for Form 8949?
Should one combine all the different accounts into set of up to the 6
possible different categories. Or alternately, treat all the different accounts
separately and only combine them on Schedule D.
Thanks in advance for any advice on this matter...................

“Should one combine all the different accounts into set of up to the 6 possible different categories. Or alternately, treat all the different accounts separately and only combine them on Schedule D.”----->Assume that all of them are subject to LTCG , then as you said, you need to treat all the different accounts separately on form 8949 line 3 , depending on the situation and combine them on form 8949 kine 4 and Schedule D line 15.

Thank you for the quick reply!
Just to clarify, assume there are four (4) accounts. Each account has the 6 possible categories that need to be reported. One would need to file using the 24 different categories on 12 separate 8949 forms. Is this correct? Then one would report the totals on 1 Schedule D.
Thanks for your help in advance..............

“Just to clarify, assume there are four (4) accounts. Each account has the 6 possible categories that need to be reported. One would need to file using the 24 different categories on 12 separate 8949 forms. Is this correct?”---->Then I guess so; as long as you have a lot of transactions, use as many Forms 8949 as necessary to report all of them, but make sure that each Form 8949 includes only the type of transactions described in the text for the box you checked (A, B or C).