Reading BussinessWeek at the Gym during my visit last week was a treasure trove of information. In addition to learning about Chuck Feeney, I learned something new about the Mortgage Deduction that I didn’t know about. Of course this piece of information is less than beneficial.

Most people typically think of all the mortgage interest as deductible, assuming it falls under the 1 million dollar cap. However this is not true for the many individuals who have refinanced to take cash out of a highly appreciated home. Refinanced mortgage interest is only deductible to the amount of the original mortgage.  For instance let’s say I purchased a house 20 years ago for 100k with a 80k mortgage, and now it’s worth 500k.  I then do a cash our refinance for a total of 300k.  I can only deduct the interest on the original 80k, not the new balance of 300k. However, according to the article in BusinessWeek and my own reading of the IRS Publication 936, it’s possible to deduct the interest on another 100k if it’s in the form of a second mortgage, or home equity line.

I’m generally not a fan of the cash out mortgage, and this is yet another reason not to do it. As is, I don’t advocate taking a course of action purely because of tax issues, and too many people push taking out large mortgage because “it’s deductible.” Taxes are an important part of the financial decision of making process and tax consequences should shape decisions. Decisions should not however ever be made solely to avoid taxes.  In this case taking a cash out mortgage may not even be the tax deduction boon one would think.

Also, I’m under the Big Tent at My Two Dollars in the 106th Carnival of Debt Reduction, my article on Mary’s Ann’s Makeover is featured.  Please take some time to visit David’s blog, My Two Dollars.