Final answer:
The statement is true; a principal can revoke a healthcare power of attorney at any time as long as they are mentally competent, typically through a written notice or a clear act of revocation.
Step-by-step explanation:
True, with healthcare power of attorney (also known as a healthcare proxy), the principal has the right to revoke it and invalidate it at any time as long as they are mentally competent. This type of legal document allows the principal to appoint an agent to make healthcare decisions on their behalf should they become incapacitated or unable to communicate their wishes directly.
To revoke it, the principal must communicate their decision through a written revocation, by creating a new healthcare power of attorney, or by any act demonstrating a clear intent to rescind the power, such as verbally expressing the revocation in front of witnesses, or destroying the document.