@pingguo38 , assuming that you are all US persons ( citizen/Green Card/ Resident for tax purposes),
1. the depreciation schedule for the property continues as if it was with the original owner ( because in case of a gift, the donee's basis is the same as the donor's basis at the time of the gift ). The claiming of the depreciation is generally based on the number of days owned by each -- donor and the donee/ recipient.
2. Absent and contravening facts, it may be easier to work as if the property was transferred on 01/01/2021 ( including rental income , expenses etc. ) --- it is cleaner and as long there is no double binning , there is no issue.
3. If the property is renting at a loss ( after accounting for depreciation), then the passive loss limitation may come into play and there could be a windfall advantage to one party ( based on the claimed transfer of ownership date ) -- IRS would object to that, if and only if the facts are diff.
Does this help? Is there more I can do for you ?
pk
