Does the FBAR apply to accounts where I only have power of attorney for a relative?

Possibly. The FBAR covers accounts in which you have a financial interest or signature or other authority, and holding a power of attorney that lets you control or direct disbursements from a relative's foreign account can constitute signature authority even if you own none of the money. If you can instruct the bank to move funds, you likely have a reporting obligation for that account once your overall foreign totals exceed $10,000. This surprises adult children who help manage an elderly parent's accounts back home. The value you report is the account's maximum balance during the year, not your share, since you have no ownership share. When you take on POA over foreign accounts, factor the FBAR into your responsibilities, and review the FinCEN FBAR instructions or ask a professional about your specific authority.