TOOLKIT FOR PARENTS · AGES 14–18
Estate Planning Essentials: Ages 14–18
The estate planning conversation shifts again as a child approaches legal adulthood.
The core documents and the gifting and trustee decisions addressed earlier remain in place, but a new and often difficult question moves to the center of the plan: what happens, legally, the moment a child turns 18. Under the law, adulthood arrives on a birthday regardless of a young person’s actual level of independence, and families need a plan in place before that date, not after it.
Why Age 18 Changes Everything Legally
At 18, a child becomes a legal adult with the right to make their own medical, financial, and legal decisions, even if their disability means they need significant support to exercise those rights safely. Parents lose the automatic legal authority they had while their child was a minor. Without a plan in place, a family may find itself locked out of medical appointments, financial accounts, or school-related decisions at the exact moment their child needs continued support the most.
This is also the point at which Supplemental Security Income (SSI) eligibility is reevaluated using adult disability standards rather than the standards applied to children, which makes it a good moment to revisit benefits planning alongside the legal planning described below.
Guardianship and Its Alternatives
Guardianship allows a parent or another appointed adult to retain legal decision-making authority for an adult child who cannot safely manage their own affairs. It is often necessary, but it is not automatic, and it is not the only option.
Full guardianship transfers broad decision-making authority to the guardian and is typically pursued when a young adult cannot reasonably manage medical, financial, and personal decisions independently. Limited guardianship narrows that authority to specific areas, such as medical decisions or finances, while leaving the young adult free to manage other parts of their life independently. Supported decision-making, a lighter-touch and increasingly recognized alternative, allows a young adult to retain full legal authority while formally designating trusted people to help them understand and make decisions, without transferring that authority away from them.
Which approach fits depends entirely on the individual, and it is worth approaching this decision deliberately rather than defaulting to full guardianship out of caution. The process typically involves a court proceeding, and in many states requires input from a medical or psychological evaluation, so timing matters. Families are generally better served starting this conversation well before the 18th birthday rather than in the weeks immediately before it.
Reviewing the Plan as a Whole
Turning 18 is also a natural point to revisit decisions made earlier. A Special Needs Trust established years ago may need adjusting now that a family has a clearer sense of the young adult’s likely living situation, income, and level of independence. Power of attorney documents, health care proxies, and beneficiary designations should all be reviewed to confirm they still reflect the family’s current circumstances rather than assumptions made when the child was much younger.
None of this needs to happen in isolation from the guardianship decision. The two are closely linked. A young adult under a full guardianship will typically need their legal and financial documents structured differently than one operating under supported decision-making, and getting the sequence right avoids having to redo documents shortly after they are signed.
A Working Reference for the Transition Ahead
As your child approaches adulthood, the Letter of Intent becomes a working reference for whoever supports them through that transition. Download the fillable template below and keep it current as legal and vocational decisions take shape.
Ready to Plan for the 18th Birthday?
Legal adulthood arrives on a date, not when a family feels ready. Let’s make sure guardianship, documents, and benefits are all in place before it does.