Can a Power of Attorney Expire?

No. However, as your power of attorney gets older, financial institutions become more wary. Historically, powers of attorney have been subject to abuse, so, understandably, banks and other financial institutions want to make sure that the named agent is still authorized to conduct business on behalf of the principal. In other words, they want to make sure the principal has not died or revoked the power of attorney.

Typically if an agent walks into a bank with a two year-old power of attorney, the bank will request that the agent obtain an 'attorney's affidavit' before allowing the agent to conduct business on behalf of the principal. The affidavit will say something like: The Principal is my client. To the best of my knowledge, the power of attorney is valid, and the principal has not died. Interestingly, other states have statutes requiring financial institutions to honor powers of attorney and protecting them when they do. As of this date, Massachusetts does not have such a law.

UPDATE:  Massachusetts has adopted the Uniform Probate Code, and it will become effective in parts, beginning in 2010.  Under the new Chapter 190B, Sections 5-506 and 507:

Section 5-502.[Durable Power of Attorney Not Affected By Lapse of Time, Disability or Incapacity.]

All acts done by an attorney in fact pursuant to a durable power of attorney during any period of disability or incapacity of the principal have the same effect and inure to the benefit of and bind the principal and his successors in interest as if the principal were competent and not disabled. Unless the instrument states a time of termination, the power is exercisable notwithstanding the lapse of time since the execution of the instrument.

 Section 5-506.[Enforcement.]

The attorney in fact under a durable power of attorney is authorized to prosecute legal action for damages in behalf of the principal in the event of an unreasonable refusal of a third party to honor the authority of a valid durable power of attorney.

Section 5-507.[Protection; Third Parties.]
No third party acting in good faith reliance on a durable power of attorney shall be held liable for action taken in such reliance.

This new language should help reduce instances where banks and other institutions refuse to honor a POA because of its age.  For more information about powers of attorney, visit our Massachusetts Estate Planning Discussion Forum.