This is an OLD post, but a response to @hixen26 anyhow (the post on March 3 2022, at 3:10PM) , and for anyone encountering this too:
The $1000 in your box 1a is not $1000 each, it might be $700 from one fund and $300 from the other. You have to look closer at your supplement sheets to see what came from each.
Unless you held ONLY those two funds, the $$ in box 1a can also include $$ from stocks, and other mutual funds, so you really have to delineate where all the $$ came from before making such calculations.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
