Do Half Siblings Inherit the Same as Full Siblings in Washington?

Your brother dies without a will. He never married and had no children, and both of your parents are gone. Then someone at the funeral asks whether your father's daughter from his first marriage "counts" the same as you do.

The short answer is yes. Under RCW 11.04.035, relatives of the half blood inherit the same share they would have inherited if they were of the whole blood. A half sister takes the same share as a full sister. There is one exception, and it matters a great deal when family property is involved: property the person who died received from an ancestor does not pass to half-blood relatives who are not of that ancestor's blood.

When Do Siblings Inherit in the First Place?

Sibling inheritance only comes up when someone dies without a will, or with a will that fails to cover all of their property. In that situation RCW 11.04.015 sets the order of who inherits, and siblings are well down the list.

Children and other descendants come first. If the person left no descendants, the estate goes to the surviving parent or parents. Only when there are no descendants and no surviving parent does RCW 11.04.015 reach the "issue of the parent or parents," which is the statute's way of describing brothers and sisters and, if a sibling has already died, that sibling's own descendants.

A surviving spouse or state registered domestic partner changes the math. The spouse receives all of the community property. For separate property, if there are no descendants but a parent, a sibling, or a sibling's descendant survives, the spouse takes three quarters, and the remaining quarter goes to the parents or, if neither parent is living, to the siblings. So for a married person with no children and no living parents, brothers and sisters share one quarter of the separate property and nothing else. The broader scheme, including how community and separate property are sorted, is covered in what happens if you die without a will in Washington.

A half sibling is the child of one of your parents, so a half sibling falls inside that group on the statute's own terms. RCW 11.04.035 then settles how much each one takes.

The General Rule: Equal Shares

RCW 11.04.035 says that kindred of the half blood inherit the same share they would have inherited if they had been of the whole blood. Washington does not give a half sibling a half share, and it does not rank full siblings ahead of half siblings.

The same holds one step down. If a half sibling died before the person whose estate is being settled and left children, those nieces and nephews step into their parent's place under RCW 11.04.015, just as the children of a full sibling would. If terms like "issue" and "representation" are new to you, the article on what heirs, issue, and personal representative mean in a Washington will explains them.

Stepsiblings are a different matter. A stepsibling shares no parent with you, so a stepsibling is not the issue of either of your parents and has no place in the sibling tier of RCW 11.04.015.

The Exception: Property That Came From an Ancestor

The equal-share rule in RCW 11.04.035 comes with an "unless." It does not apply when the inheritance came to the person who died "by descent, devise, or gift" from one of his or her ancestors, or from relatives of that ancestor's blood. In that case, the statute says, all those who are not of the blood of that ancestor are excluded from that inheritance.

In plain terms: if the person who died received property from a parent or grandparent, whether by inheriting it without a will, receiving it under a will, or getting it as a lifetime gift, then a half sibling who is not related by blood to that parent or grandparent does not share in that particular property. The half sibling still shares equally in everything else.

The Washington Supreme Court applied the exception strictly in In re Estate of Little, 106 Wn.2d 269, 721 P.2d 950 (1986). A woman died without a will owning waterfront land that her mother had deeded to her. The people competing for it were half-blood relatives on her father's side, who were closer relatives, and more distant whole-blood cousins on her mother's side. The court held that under RCW 11.04.035 the half-blood relatives' rights in ancestral property are cut off even when the relatives competing against them are more distant, and that the ancestor whose blood counts is the one the property immediately came from, in that case the mother. The court then sent the case back to the trial court to decide whether the mother's deed had really been a gift, because the answer to that question decided whether the land was ancestral property at all. The court ruled only on real estate and did not decide whether the exception also reaches money or other personal property.

Two practical points follow. The exception can remove a half sibling from a piece of property entirely, not just reduce a share. And the paper trail matters: how the person acquired the property, and from whom, can become the whole dispute.

The statute also protects adopted children on this point. A child lawfully adopted by someone who is of the ancestor's blood is treated as being of that ancestor's blood. Adoption has its own inheritance rules, covered in whether adopted children inherit from their birth parents in Washington.

A Worked Example

Dana dies in Everett without a will. She was never married, had no children, and both of her parents have died. She is survived by her full brother, Eli, and by Faye, her father's daughter from an earlier marriage. Dana and Faye share a father but not a mother.

Dana's estate has two main assets: savings she built from her own paychecks, and a house her mother left to her by will ten years ago.

The savings did not come from an ancestor, so the general rule of RCW 11.04.035 applies. Eli and Faye are both issue of Dana's parents, and they split the savings equally.

The house is different. It came to Dana by devise from her mother. Faye is not of the mother's blood, so RCW 11.04.035 excludes Faye from that inheritance, and the house goes to Eli alone. If the house had come from the father the siblings share, Faye would be of that ancestor's blood and would take half.

A Will Replaces All of This

Everything above is a default that applies only when there is no will. A person who wants a half sibling and a full sibling treated identically, or who wants to leave an inherited family home to a particular person, can say so in a will, and the will controls instead of the half-blood statute. The same is true in reverse for someone who wants to leave a sibling out.

Sorting Out a Sibling Inheritance

Half-sibling questions usually surface after a death, when nobody is sure who the legal heirs are or where a piece of property originally came from. If you are settling the estate of a brother or sister, or planning your own estate in a blended family, the Law Office of Chad Foster can help you work through who inherits and why. Call 425.785.8679 to talk with a Snohomish County probate attorney.