You can pay off the mortgage. The bottom line is that it costs you a lot more money in opportunity costs to pay it off as oppsed to conservatively investing it over the long hall. Addionally it is riskier to have money tied up in a home than having a large diversified portfolio of investments. Transfer the risk to the bank and if you are smart you will never worry about the marshall coming because you ahve assets to make 30 years woth of mortgage payments