I would get a notarized letter stating the grandparents have permission to act as medical surrogates in your absence. A grandparents' medical consent form allows a parent or legal guardian to hand over all responsibility regarding their child's healthcare decisions.Washington Child (Minor) Medical Consent Form. Use our Child Medical Consent form to let someone make medical decisions for your child in your absence. Everything you need to write a declaration letter to the judge in your custody case: an example, a downloadable template, an outline and tips. This includes day trips and travel where a child will be with only 1 parent for part of a trip. You could create a permission form for parents to fill out before leaving the state with the child. Consider hiring an attorney to draft this.