You cannot get a power of attorney for someone who is already mentally incompetent. Every state requires the person signing the document, the principal, to have mental capacity at the moment they sign. Once capacity is gone, that door has closed, and the remaining option is a court-supervised guardianship or conservatorship. There is one narrow exception worth checking before you give up on a power of attorney: if the person has a condition like dementia but still experiences genuine periods of clarity, a document signed during one of those “lucid intervals” can be valid.
What Capacity Means at the Moment of Signing
A power of attorney is a voluntary delegation of authority. The principal is choosing to let someone else handle their finances, healthcare, or both. That choice only has legal meaning if the principal genuinely understands what they’re agreeing to. Courts and financial institutions treat a power of attorney signed by someone without capacity as void from the start.
The capacity standard isn’t as high as many people assume. The principal doesn’t need to manage their own checkbook or remember what day it is. At the moment of signing, they need to understand three things: the nature of the document, the powers it grants, and who they’re appointing. Someone who cannot grasp that they’re handing control of their bank accounts to their daughter, for example, hasn’t really consented to anything, and a document signed in that state won’t survive challenge.
The Lucid Interval Exception
Progressive dementia and serious mental illness are not always constant. A person may drift in and out of clarity, and the law accounts for that. If the principal genuinely understands what they’re signing during one of those windows, the power of attorney can be valid even though they lack capacity most of the time.
The practical problem is proof. A document signed by someone with a dementia diagnosis invites challenge later, especially from relatives who disagree with the choice of agent. Getting a physician to examine the principal on the day of signing and put their capacity assessment in writing is critical. Without contemporaneous medical documentation, a lucid-interval power of attorney is fragile. With it, the document has a real chance of standing up.
If there’s any doubt about capacity, work with an attorney who has handled these signings before. They know what a bank or a probate judge will want to see if the document is later questioned.
Guardianship When Capacity Is Already Gone
If the person has clearly passed the point where they can understand what a power of attorney is, a family member or other interested person must petition a court for guardianship. Some states call this conservatorship. A judge evaluates whether the person is truly incapacitated and, if so, appoints someone to make decisions on their behalf. The incapacitated person, called the “ward,” is entitled to legal representation during the proceeding.
Guardianship is the court doing what a power of attorney would have done privately. The difference is judicial oversight at every step. The guardian typically must post a bond, file an inventory of the ward’s assets, and submit annual reports detailing how the ward’s money was spent and how their care is going. The court can require approval before the guardian sells property, moves the ward, or makes other major decisions. That oversight protects vulnerable people, but it costs time, money, and privacy.
What Guardianship Costs
Guardianship is substantially more expensive than a power of attorney, which typically runs a few hundred dollars to draft. Attorney fees for a guardianship petition generally range from $1,500 to over $10,000 depending on complexity and whether the petition is contested. Court filing fees add a few hundred dollars. If the court appoints a guardian ad litem, an independent person who investigates the ward’s situation and reports to the judge, those fees can add several hundred to several thousand dollars more. Ongoing costs include annual bond premiums and filing fees for required court reports. A contested guardianship, where family members disagree about who should serve or whether guardianship is even necessary, can cost dramatically more.
Emergency Guardianship When Time Is Short
When the situation is urgent, such as when an incapacitated person’s health or finances are in immediate danger, most states allow a petition for emergency or temporary guardianship. Courts can act on these petitions within days rather than months. The temporary guardian’s authority is limited in scope and duration, typically lasting around 90 days while a full guardianship proceeding gets underway. The bar is higher than for a standard petition: the petitioner usually must show imminent harm, not just a general need for help.
Less Restrictive Alternatives to Full Guardianship
Full guardianship strips away most of a person’s legal rights. Courts increasingly look for less drastic options when someone still has partial capacity. A limited guardianship restricts the guardian’s authority to specific areas, like finances, while leaving the person free to make their own decisions about other matters, like where to live. A growing number of states also recognize supported decision-making agreements, which let a person with diminished capacity formally designate trusted supporters who help them understand and make their own choices rather than making choices for them. These alternatives are worth exploring with an attorney before filing for full guardianship.
If You’re Reading This Before Capacity Is Gone
Anyone still able to understand what they’re signing can avoid guardianship entirely by executing a durable power of attorney now. A standard power of attorney loses its effect the moment the principal becomes incapacitated, which makes it useless for the situation most families worry about. A durable power of attorney includes language keeping the agent’s authority intact even after the principal loses capacity. That is almost always the document families actually want.
Two varieties usually work together. A financial power of attorney covers property and money: bank accounts, investments, real estate, bill payments, and tax filings. A medical power of attorney, sometimes called a healthcare proxy, lets the agent make treatment decisions when the principal can’t. Most people need both, and they don’t have to name the same agent for each one.
A durable power of attorney typically takes effect the moment it’s signed. Some people prefer a “springing” version that only activates when a physician certifies the principal is incapacitated. The tradeoff is friction: banks and other institutions may demand proof the trigger has been met before they’ll cooperate, which can delay the agent exactly when speed matters. Some states have moved away from springing powers entirely under the Uniform Power of Attorney Act, defaulting to immediate effectiveness instead.
Execution requirements vary by state. Most states require notarization for a financial power of attorney. Many also require one or two witnesses. Medical powers of attorney commonly require two witnesses. Getting the document both witnessed and notarized is the safer path since it reduces the chance a third party will reject it later. Confirm the document includes explicit durability language stating the power of attorney survives incapacity.
One Boundary to Know: Social Security Won’t Accept Either Document
Whether you end up with a durable power of attorney or a court-ordered guardianship, neither one gives you authority over the person’s Social Security or SSI payments. The Social Security Administration does not recognize a power of attorney as authority to manage those benefits, and even a court-appointed guardian must go through SSA’s separate process. You have to apply directly with SSA to be named as the person’s “representative payee,” regardless of any other document you hold.1Social Security Administration. Frequently Asked Questions for Representative Payees A representative payee has specific obligations, including keeping benefits separate from their own money and filing annual accounting forms with SSA.2Congress.gov. Social Security: Representative Payees and Power of Attorney Plan on filing that application as a separate step.