How to show house cost basis step up due to death of spouse.

[Bsch4477]

You don’t have to show it. Just keep good records in the unlikely case of an audit. 

[GeorgeM777]

Unless you are selling the property, there is nothing to report on a return.  However, going forward, it may be helpful to ascertain your basis now in the event of a sale in the future, or whether the property is converted into income producing property, i.e., a rental property.   What was the form of the property ownership?  For example, did the spouses own the property as joint tenants with rights of survivorship?   

@VN9