Turbo tax will let you go in and do 2015. If you haven’t gotten w-2’s yet, you just need your last Dec paystubs (year to date) for you and new spouse and you should get a very close estimate.
You could also just use the amounts of tax withheld from the final 2015 pay stub (year to date).
It will be difficult to do since you did not last year. Essentially, your cpa can estimate using you final pay period advice stub. It has the income and tax info on it.
if the 2015 withholding has been accurate, yeah. But there was an active thread on here recently where $10,000+ was being withheld for 2015, and probably all of that was going to be refunded.