CA (540) Interest Income Adjustment for California by TurboTax Seems to be Wrong!

[fkhalilz]

A portion of  my total interest income comes from US treasuries. This has been clearly entered into the 1099-INT forms of TT.  Since California does not tax interest income from US treasuries, I expected this exact amount to be shown in the CA (540) as a subtraction from the total interest income. However, when I viewed the form CA (540) produced by TT, I noticed that the amount used for the subtraction is slightly less. I cannot determine how TT has arrived at the lesser figure. Is this a TT bug? If not, how did TT arrive at this smaller figure? Is there a hidden formula? Normally, you can find the source of data in the forms by right clicking on the number while viewing the Forms. However, I cannot find the source of the data in this case.

Thanks for your help!

[fkhalilz]

Hello Tax Experts,

I hope you can help me with this issue.

Once again, I have multiple  20251099-INT forms that I have received. Some of them have values in Box 3 representing the interest income from US Treasury Obligations.  It is my understanding that the sum of values in Box 3 of all 1099-INT forms should be the subtraction amount shown in CA (540) form. But as I mentioned before, the number appearing there is slightly less.

Have you heard of any similar problem before? In your opinion what is the best course of action?

Thanks!