WHEN IT'S NOT A GOOD IDEA TO PAY OFF YOUR HOME MORTGAGE

In order of importance here are the places you need to put your financial attention first:

Take the cards off the table: Pay off credit cards with any high interest rates — especially today, as there is now a huge discrepancy between credit cards interest rates of 13 percent to 23 percent and a 4 percent mortgage interest rate. Besides that, you can deduct your mortgage interest but you cannot deduct the interest you are paying on credit card debt.
In case of emergency: You need to build an emergency fund. I recommend one year of living expenses. Yes, today's job market is improving; however, if you suddenly find yourself facing a layoff, you need to be prepared to sustain one year of living expenses.
Build up for retirement: Are you able to make the maximum yearly contributions to your retirement accounts? 401(k), IRA or an equivalent? Ask you accountant what the maximum allowable is for you and go for it.
Get the kids to school: Ah yes, the kids, their schools and their college funds. Depending on how many children you have, how old they are and what type of college enrollment expectation they have, you need to be making adequate contributions to those 529 plans or other college savings accounts.
You may live a long time: Your  mom is 97 years old, and your aunt just turned 100. So you see how your money could run out before your health does.   Another priority investment you need to be making each year is toward long-term health-care insurance. It is not as costly when you start it in your 30s or 40s. But if you didn't get around to it till your 50s it will take a hit out of you budget each month.