A fixed-rate mortgage payment is not actually fixed β while your principal and interest stay the same, property taxes and insurance rise over time, so your total monthly payment climbs.
Lenders collect property taxes and insurance through your monthly escrow payment. When local tax assessments or insurance premiums rise, your servicer increases escrow β even though your loan's principal and interest never change on a fixed rate.
What the data shows
How this tool models growth
P&I is held flat using standard amortization. Property tax starts at home price Γ your state's Census effective rate and compounds annually. Insurance starts at 0.35% of home value. PMI (~0.5%/yr of loan) applies below 20% down until scheduled amortization brings the balance to 78% of the original home value (automatic HPA termination). You may qualify to request removal at 80% LTV sooner, but this tool models the conservative automatic rule β not appreciation-driven cancellation.
Likely scenario assumptions: property tax 4%/yr, insurance 6%/yr, home value 3.5%/yr β all visible and adjustable in the tool above.