The Treasury Inspector General for Tax Administration, in a recent report, criticized the IRS for what it said was a lack of specific plans to replace and decommission legacy systems. 

The Inflation Reduction Act of 2022 gave the IRS additional funding to make improvements to its information technology infrastructure. Part of this was to retire old legacy systems and introduce newer, more modern replacements. To do so, the IRS said it would implement some of the recommendations TIGTA made on this very subject in a 2020 report. 

While two of the recommendations — to implement a policy requiring system owners to provide and update system information in the as-built-architecture, and to ensure that all systems are included in the ABA with complete and accurate information — were successful, TIGTA was more critical overall. 

For instance, while the IRS had recently identified 107 legacy systems as candidates for retirement, this was out of 334 overall; furthermore, of those 107 systems, only two have specific decommission plans. There are no plans for the remaining 105 systems. While the IRS had established the Technology Retirement Office within the Enterprise Services function in August 2021 to support these efforts, the office was shut down in January 2023 when its mission shifted from tracking the progress of system retirements to the strategic planning support of system decommissioning, such as providing architectural support services. 

“Without an enterprise-wide program, there is risk of an increasing use of resources to operate and maintain aged systems,” said TIGTA. “The IRS’s spending on operations and maintenance for its information technology infrastructure increased 35 percent from $2 billion in Fiscal Year 2019 to $2.7 billion in Fiscal Year 2023 and will likely continue to increase until a majority of legacy systems are decommissioned.”

Further, TIGTA had stated that the IRS was not uniformly applying its enterprise-wide definition to identify its inventory of legacy systems and therefore, said TIGTA, the IRS does not have a complete and accurate inventory of legacy systems. Using the IRS’s own definition of a legacy system (namely, an application age of 25 years or older or written in an obsolete programming language), TIGTA identified 344 systems as legacy. However, a review of a March 2024 report determined that the IRS incorrectly identified five additional systems as legacy. 

Staff said this happened because while the query searched for the application age and programming language fields, it also searched the system name field for the obsolete programming language. As a result, the query incorrectly identified a system as legacy for systems whose name included an obsolete programming language. 

“Without an accurate and a complete inventory, the IRS will be unable to effectively manage its legacy systems,” said TIGTA. 

In response to this finding, IRS Enterprise Architecture Office personnel stated that they updated the query to correctly identify all legacy systems. A second TIGTA review, though, found two additional systems that had not been identified as legacy but should have been, bringing the total number of legacy systems to 346. The IRS updated the system again as a result of the inspectors’ findings and, as of May 2024, TIGTA’s review of the report determined that all 346 legacy systems operating in the production environment have been identified correctly. 

TIGTA recommended that the Chief Information Officer should: 1) re-establish the Technology Retirement Office or implement a similar enterprise-wide program to identify, prioritize, and decommission legacy systems, and 2) ensure that the definition of a legacy system is properly applied and programmed in the query to correctly identify all legacy systems.

The IRS partially agreed with the first recommendation and plans to deliver a roadmap, which will reflect milestones toward delivering new capabilities, and work to decommission legacy systems as new capabilities become available. The IRS agreed with the second recommendation and plans to update the programmed query definition.