to calculate my AGI and subsequent MAGI do I subtract my husband's 401-k contribution and our health benefit cost? How about TAP contributions and dependent care?

Definitely yes on the 401(k). Probably health insurance and dependent care. I wouldn't know a TAP if I fell over one in the street.

The easiest thing to do is to wait until he gets his W-2. All this work is done in coming up with the Box 1 number, which is the amount that contributes to AGI. Second easiest would be to compare his final paystub for 2006 with his 2006 W-2. That will show you which deductions are pre-tax.

Phil