What action must a fiduciary take if additional property is discovered after the initial inventory?

The action that a fiduciary must take when additional property is discovered after the initial inventory is to file a supplemental inventory and appraisal. This requirement ensures that all assets held in the estate or trust are accurately documented and evaluated. Filing a supplemental inventory provides transparency and fulfills the fiduciary's obligation to manage the estate or trust appropriately.

By appraising any newly discovered property, the fiduciary confirms its value, which is critical for the purposes of distribution to beneficiaries, payment of debts, and overall estate management. This process is vital to maintaining the integrity of the fiduciary's actions, as it helps ensure that all parties involved have a clear and updated understanding of the estate's assets.

The other options do not align with the legal and fiduciary responsibilities. For example, merely notifying the court without a formal filing would not provide the necessary documentation or appraisal required for proper asset management. Waiting until the next annual report would delay the necessary updates and potentially mislead beneficiaries about the estate's current status. Excluding new property from reporting would breach the fiduciary's duty and could lead to legal consequences. Therefore, filing a supplemental inventory and appraisal is the appropriate and necessary action.