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Adult guardianship guide | Washington Law Help

Adult guardianship guide

Northwest Justice Project

Reviewed for legal accuracy on April 1, 2026

Learn when and how someone can become an adult’s legal guardian, what the adult’s rights are, and what the guardian’s responsibilities are.  

1. Fast facts

What is adult guardianship?

Adult guardianship creates a legal relationship between someone age 18 or older who can’t manage their health, safety, finances, and so on (called the Respondent) and another adult whom a superior court judge appoints to make decisions about that person’s personal affairs. Once appointed by the court, the guardian can make decisions about the Respondent’s living situation, medical treatment, and services, and can apply for benefits for the Respondent. 

More than one person can be guardian. 

Is adult guardianship right for my relative or friend? 

It depends on the Respondent’s situation and whether other available options won’t work. Here are some examples where guardianship might make sense: 

Example 1: Mo’s parent has Alzheimer’s and can no longer take care of themselves and their home. They can no longer communicate and manage their health care, and they need help at home. There’s no power of attorney. A social worker is involved and suggests Mo file for guardianship. 

Example 2: Les’s child, Mae, is 17 and has disabilities that prevent them from understanding and communicating. Mae’s special education teacher has suggested Les file for guardianship once Mae turns 18, because Mae could be taken advantage of and other care providers won’t communicate with Les once Mae turns 18.

Example 3: Stevie, who is homeless, is in the hospital, in a coma, and with a broken leg that needs fixing. Stevie has no immediate family or friends but does have an adult niece. Someone must approve treatment for Stevie’s leg. 

Guardianship isn’t right for every situation. Whether you’re asking that you or someone else be made guardian, you must show that there’s clear and convincing evidence of all these: 

  • The Respondent can’t meet their basic needs due to an inability to receive and evaluate information and communicate decisions, even with support or help. 
  • There’s some risk to the Respondent. 
  • No less restrictive alternative will help. 

A court may not appoint a guardian if the Respondent’s needs can be met in other ways. It’s not enough just to show that you just disagree with or would make different decisions than the Respondent.

Who can file for guardianship, and where? 

Anyone age 18 or over can file for adult guardianship. But to be appointed guardian, you must be at least 21 years old. You can file for guardianship and name someone else to be appointed. 

You must file for adult guardianship in the Superior Court of the county where the Respondent lives or, if the Respondent has been ordered committed to an institution, in the county where the institution is located.

2. Guardianship process