A tax law change in 2004, which became effective for tax years 2005 and beyond, resulted in this nice benefit. Making a change prior to 2005 probably won't do you any good. Only people with a very narrow income range benefited previously. It can't hurt to run the numbers. However, if, say, the benefit occurs in 2003, but not in 2004, and you change 2003, you must then also change 2004 and pay back tax. Thus, it may not be worth the effort.