How do I adjust my 1099 DIV income to reflect a portion of a mutual fund that is exempt in California? Target date fund had CA tax-exempt holdings that need to be exclud

What box is it in?  And what company?  Is it Vanguard?  I have Vanguard and know them.  

And...what was the exact name of the fund the $$ came from. 

Some Bond funds did not hold enough CA-specific bonds to allow the exemption.  CA restricts the ability to exempt the $$ to those bond fund that hold mostly CA-Specific bonds.

California, and Minnesota require that the bond fund hold at least 50% of their holdings be in their own state's bonds, before you can break out that state's $$ for possible lower state taxation.  Illinois, essentially,  doesn't allow it at all.