Thanks for your response but it doesn't seem to resolve my issue. I have a Calif trust for which i'm preparing a 1041.  Assume I have municipal bond interest on Calif bonds of 10,000 and amortizable bond premium of $4,000 with respect to such bonds. Assume further that I also have municipal bond interest on bonds issued by other states of $7,000 and amortiz bond premium of $1,000 with respect to such bonds. For federal purposes I would have 17000 of exempt interest reduced by 5000 of bond premium.  For Calif purposes I should be able to report as taxable $6000 ($7000 of interest less $1000 of corresponding premium). I put $17000 in the Total Municipal bond interest box (with a designation of "US") and I put 10000 in the in state box.  There is a single amortizable bond premium box. I use the drop down and put 4000 in one box and label that as "CA." (I put the total premium in another box.) But that gives me the wrong answer for Calif.  Is there another way to do this?