Can a taxpayer claim the non business bad debt for being scammed by a contractor that never completed job in home? He never returned and homeowner paid him > $17,000

[qbteachmt]

It's not bad debt; it's personal theft loss and this is not deductible. See the IRS resources, such as:

https://www.irs.gov/taxtopics/tc515

[George4Tacks]

File a claim with your state contractors licensing agency. File at least in small claims court to establish a valid debt, then maybe you can claim a casualty loss due to theft.