I received a revised form 1098 which lists mortgage insurance premiums which my first one did not list. Do I need to amend my return that I have already filed?

It depends. You can deduct the mortgage insurance premiums, because the deduction was extended to 2017, so you might be due a refund if you amend. The deduction is limited, however if your adjusted gross income is more than $100,000, and eliminated entirely at adjusted gross incomes above $109,000. 

You should check to see if this deduction benefits you, and file the amended return (1040X) if it does.

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