My wife does not pay into social security because she is a teacher in Nevada. How does turbotax account for this?

when you entered the w-2 was there a 0 in the FICA income section?  If yes, did you input it into TT correctly?

Box 3 and 4 are both blank. However, our tax liability estimate seemed to jump very high as soon as I finished entering her w-2 info, which made me suspect TT is expecting a number greater than 0 in box 4.

So you input 0 in box 3 and 4.  Box 2 should have federal taxes withheld.   There is no calculation for additional social security taxes.....  Turbotax handles this fine.  Possibly your income moved you up to a higher tax bracket subjecting you to limitations on deductions or AMT?

Thanks, I think that's the answer. Since her income was entered after mine, it pushed a large portion of our income into a higher tax bracket. Thanks!