Final answer:
Interest on home equity loans and HELOCs is deductible when used for buying, building, or substantially improving the securing home, fitting the definition of acquisition indebtedness.
Step-by-step explanation:
The deductibility of interest related to home equity loans and home equity lines of credit (HELOC) is contingent upon how the borrowed funds are utilized. Specifically, the interest is deductible only when the funds are used for acquiring, constructing, or significantly improving the residence that secures the loan. These actions would then fall under the category of acquisition indebtedness, which makes the interest potentially deductible.