Pacun I respectfully disagree. Below is a section from Pub 551 Basis of Property. Yardley CPA, I see you are in PA and I am assuming the rentals are not in a community property State. I would take some time to research a bit further but everything I have looked at leads to the same example as in the pub. There are also examples of how to begin the depreciation on the new basis as well. Based on your statement of two properties being 20 years old, I am assuming they are not depreciated out. However, the depreciation taken before the death of the spouse will be used to determine the new basis. I have not used ATX for a number of years now so I can't help you with the proper way to handle it. Maybe Jack or someone still using ATX will chime in and help.
Property Held by Surviving Tenant
The following example explains the rule for the basis of property held by a surviving tenant in joint tenancy or tenancy by the entirety.
Example.
John and Jim owned, as joint tenants with right of survivorship, business property they purchased for $30,000. John furnished two-thirds of the purchase price and Jim furnished one-third. Depreciation deductions allowed before John's death were $12,000. Under local law, each had a half interest in the income from the property. At the date of John's death, the property had an FMV of $60,000, two-thirds of which is includable in John's estate. Jim figures his basis in the property at the date of John's death as follows:
Interest Jim bought with his own funds—1/3 of $30,000 cost
$10,000
Interest Jim received on John's death—2/3 of $60,000 FMV
40,000
$50,000
Minus: ½ of $12,000 depreciation before John's death
6,000
Jim's basis at the date of John's death
$44,000
If Jim had not contributed any part of the purchase price, his basis at the date of John's death would be $54,000. This is figured by subtracting from the $60,000 FMV, the $6,000 depreciation allocated to Jim's half interest before the date of death.
If under local law Jim had no interest in the income from the property and he contributed no part of the purchase price, his basis at John's death would be $60,000, the FMV of the property.