Burnham & Associates | Stephanie K. Burnham
A lot will depend on how the title to the house is held. If the house is held as Joint Tenants with Rights of Survivorship there will be no claim available to the stepchildren, unless "Mom" passes before "StepDad". If the house is held as Tenants in Common (unusual but possible) then his half of the property would be subject to Probate. His children will be entitled to a share of his estate based on the laws of intestacy, but unless he has a large amount of assets, their interest will not overcome Mom's interest as the surviving spouse. To clear up any potential issues, your Stepfather should consider preparing a Last Will and Testament.
Answer Applies to: New Hampshire
The Schreiber Law Firm | Jeffrey D. Schreiber
I am assuming the mother is deceased and the only person who has any ability to make a will is the husband. If he has a will, whatever and to whoever he distributes his property is what controls, whether or not they are relatives. If he dies without a will, then the intestacy laws of the state where he lives/the property is located will state who takes the property. Some states will allow for step children, some do not, so you would have to know what the laws is. To avoid that, sign a will which will take the place of the intestacy laws.
Answer Applies to: California