When you no longer use an asset in business, the two most likely outcomes are sale or conversion to personal use. Since you took a Section 179 expense, meaning you took the entire asset's useful life in one year rather than spreading it out over a number of years, you have to recapture the depreciation. Recapture
If in 2019 you had a five year asset that cost $1000, you would have been entitled to a deduction of $200 the first year. Since you would have taken the entire $1,000, you took $800 of depreciation you were not entitled to. You must include the $800 as income.
