We've been doing the AMT worksheet since 2010 (based on income) and have been allocating mortgage interest deduction of 43% deductible (house) and 57% (boat and college tuition) not deductible for AMT purposes all these years, and therefore have been paying AMT every year. Now we're wondering if we just should've done the AMT just for the year we did the HELOC (2006) and no other year, or still every year until the mortgage is paid off, or just for each year that we did the HELOC and the two re-fi's in 09 and 17?