A significant accomplishment during the early period of trust reform was the conversion to a commercial off-the-shelf (COTS) accounting software system. In March 1998, OST contracted with a commercial vendor to use a version of its trust accounting system that provides basic collection, accounting, investing, disbursing and reporting functions.

TFAS is an accounting and investment system that enables the automated production of account statements for individual Indians and tribal account holders. It replaced a module in BIA 's Integrated Records Management System and two OST systems. TFAS was deployed in August 1998 and was fully operational in May 2000.

TFAS allows automated trade settlements, automated payments of financial asset income, daily securities pricing and automated reconciliation. In addition, landownership and leasing accounts are being included in TFAS as part of BIA's and OST's TAAMS conversion project, to ensure that both systems contain accurate and complete information.