I'm ready to split a CA registered domestic partner return into two single returns and learned the one working partner was given numbers for imputed income from their employer for health insurance for the non working partner.  I cannot tell by looking at the W2 if the imputed income was included already.  Boxes 1, 3, 5 and 16 (state wages) are all the same.  A paystub shows employee and employer pre and post tax medical and dental deductions so it appears they are tracking the benefit but how do I know if it was included in federal income but not CA income?

Thank you