How to determine assets for estate tax purposes

I am trying to determine whether I need to file a state estate tax return for my deceased spouse.

I know that I don't have to file a federal return (Form 706) because the estate is well below 11 million dollars. But my state, Massachusetts, has a $1,000,000 threshold. Almost all of our assets (house, stocks, etc.) are in joint names. It is my understanding that these assets will not count towards the 1,000,000 because off the pass-thru for spouses. 

But I need to determine whether his state pension (which had survivors benefits) counts towards teh quantification of his assets.