Mentally, you're combining your mortgage portion of the payment with the escrow portion. They are separate, and that's why your total monthly payment can fluctuate if you pay them together. The actual mortgage terms didn't change. The portion of that payment going towards the mortgage isn't changing. When you pay taxes and insurance in escrow, you have them tacked onto your mortgage payment. So if the taxes or insurance go up, that add-on amount goes up accordingly. Contact your lender and verify why they saw a shortfall. Did your taxes go up? Did your insurance? Both? Did they send you an escrow analysis with this notice, which would be the typical process? If so, what does the analysis show? Where is the account projected to be short?