My general advice is to sign new financial powers of attorney about every 5 to 10 years. Many financial institutions commonly reject older power of attorney documents as a matter of internal policy.
My general advice is to sign new health care powers of attorney at least every 10 years. The health care directive forms in Arizona regularly adapt to law changes, so regular updates are appropriate.
If a client begins to show signs of diminished mental capacity, then annual updates to the powers of attorney are appropriate.