I am renting to family and it is well under fair market value, how and where can this affect my return and should I continue to put this under rental property.

[Carl]

When renting to family *and* at below FMV, once your rental losses get your taxable rental income to zero (and they will) no further losses are allowed and no carry over's are allowed. If you have carry overs from prior years where you did rent at or above FMV, then you lose those carry overs permanently and forever.

[Anonymous_ · Accepted solution]

Every day you rent to a family member at below fair rental value is considered a day of personal use.

See I.R.C. § 280A(d)(2)

Therefore, your property should be treated as a second home with the only deductible expenses being property taxes and mortgage interest (subject to the relevant limitations).