Your question confuses me a little bit. You could be asking about how you get the power to make substituted decisions for another person. Typically it would be through a Power of Attorney, a Guardianship and/or sometimes a state statute might allow for it (a well spouse can often make decision for an incapacitated one).
if you are asking how is substituted decision making defined, I think it is best to contrast it with the standard of best interest. You make a decision based on what the individual would want, not upon what you think would be in that individuals best interest.
In any event, if you either want the authority to be able to make substituted decisions or are concerned about making them, you should have a Wisconsin elder law attorney assist you because it can be confusing and you want to protect yourself and the person you are making decisions for.
Powers of attorney (separate requirements for health care as opposed to financial) are recognized by the Wisconsin statutes. Note that under Wisconsin law certain types of substitute decision making must be specifically authorized or that power does not exist.
If a power of attorney does not exist to allow substitute decision making, then a guardianship would be required.
There are three methods by which a person may be permitted to make decisions for another person that has been incapacitated. First, if the incapacitated person had validly executed a durable power of attorney, then the agent may act. Second, a guardianship or conservatorship is established by a court of competent jurisdiction, then the guardian or conservator can act on behalf of the ward. Third, if there is an authorization by statute.
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