Unless you revoke it or state an expiration date or circumstances under which it will expire (in the expiration section of the form), this proxy shall remain in effect indefinitely.
In most cases, there is no need to set an expiration date or term. However, if you do have a date or condition that would prompt this form to expire, you may note this on the form.
It is important to note that if you complete a new form, it will override an old form (there is no need to have previously set an expiration date). Also, if you list a spouse as your health care agent, and you divorce, the form is automatically considered to be invalid unless you explicitly note that you still wish for your ex-spouse to be your health care agent.