You can only authorize medical power of attorney over your child if you have the authority to make medical decisions on his behalf -- in other words, you may only delegate as much authority as you have. This means that you must be a custodial parent, a legal guardian, or some other party with similar authority. Regardless of your authority, you may not empower your attorney-in-fact to authorize the withdrawal of life-sustaining treatment.
When to Use It
A medical power of attorney for a child is useful whenever you have to be away from your child long enough for a medical emergency to occur. Military families and parents who travel frequently on business often use medical powers of attorney. You may execute a power of attorney in favor of a babysitter, day care provider, non-custodial parent or family member.
A medical power of attorney should state the basis of your decision-making authority over the child such as if you are the custodial parent or legal guardian. It should identify the attorney-in-fact who will be empowered to make medical decisions on behalf of the child -- and state that you are appointing him. It should clearly state the attorney-in-fact's authority, which might require considerable drafting skill. If the delegated authority is stated too broadly, for example, "to make medical decisions concerning the treatment of my child," a third party, such as a doctor, might be reluctant to honor it. If they are stated too narrowly, however, your attorney-in-fact might be left powerless in a time of need. For example, "to choose among alternative treatments in case my child is injured," could be interpreted as such that it leaves the attorney-in-fact with no authority if the child becomes ill rather than injured.
Different states have different requirements concerning the execution of a power of attorney. All require that you sign and date the form, and many require the attorney-in-fact to sign and date it as well. Some states require notarization of all required signatures, while other states require the presence of at least two witnesses who must sign the document.