<prompt> Human: Im asking this as a follow-on question from a previous question I asked. This particular piece seemed to generate a lot of responses, and the opinions seemed to split about 5050, so I thought maybe this deserved its own thread.Heres the situation: Youve got a mortgage with many years left lets say 20 and owe a sizable amount lets say 300k-500k but have a pretty good fixed rate lets say 3.5. Youre a US resident with a high-earning job lets say 120kyr, such that youre able to take good advantage of the interest deduction. Suddenly, you have the cash you need to pay off your mortgage. You won the lottery, or were gifted the money, or won on a game show; it doesnt matter how, but youve suddenly got more than enough money in your account to cover the rest of your mortgage.Do you pay off your mortgage? Or do you do something else with the money? If so, what and why?edit: Added rate.  <response>: I might not cash out investments to pay it off but I would divert cash flow to pay down the loan early. My wife and I paid off a mortgage on a 130k home in 10 years as our salary grew to about 125k. Living without a mortgage is a great feeling, it frees up so much monthly cash flow. It allows you more freedom in career decisions to either pursue higher income or scale back your workload. Weve just moved into a 480k home. We saved up a significant down payment 180k easier to do without a rentmortgage payment, took a 300k mortgage, and as soon as we sell our old home will pay down 200k onto the mortgage. From there we will make extra payments to pay it off completely in about 4 years. The way I see it, paying off the mortgage is another form of diversification. Were heavily exposed to the stock market in retirement and other investments. Paying off the mortgage is like depositing equity into our home. Looking back I wish I had paid down our first home faster consider how poorly the stock market performed during most of the time we held the mortgage 2000-2010. Paying down the mortgage would have been a better investment. 