The documents that protect an aging parent — powers of attorney, healthcare proxies, wills — must be executed while the parent still has full legal capacity. Waiting for a health crisis to force the conversation often means the window has closed, leaving families with no legal authority to act and a costly, adversarial guardianship proceeding as the only alternative. This guide covers what needs to be notarized, what the hospital and nursing home process looks like, what Massachusetts law says about physical incapacity, and how mobile notary services support elder care situations across the state.