12. Restructurings

During the three months ended March 31, 2024, we implemented a restructuring plan to better align our organization to our two operating segments: MRD and Immune Medicine. We incurred aggregate restructuring costs of $1.0 million, primarily related to one-time termination benefits and ongoing benefit arrangements, which were paid as of June 30, 2024.

During the three months ended June 30, 2024, we implemented additional restructuring initiatives which impacted certain planned software enhancements and resulted in the consolidation of certain research and development workflows. The impacted software enhancements were primarily associated with our laboratory information management systems. As part of these restructurings, we had long-lived assets that were no longer being utilized and we vacated certain leased space in South San Francisco, California. As such, we assessed the related assets for impairment by first comparing their carrying amounts to the future net undiscounted cash flows projected to be generated over their remaining lease terms or depreciable lives, as applicable. The carrying amounts were all found to be unrecoverable, thus we assessed the fair values of the assets. The extent to which the carrying amounts of the assets exceed their fair values represents the impairment costs to be recognized. As a result of our assessments, we recognized $7.2 million of impairment charges. Of the $7.2 million charges recognized, $1.1 million and $3.3 million related to the right-of-use asset and related long-lived assets (namely laboratory equipment and leasehold improvements), respectively, associated with certain of our leased space in South San Francisco, California. The remaining $2.8 million recognized related to the impairment of long-lived assets associated with our halted software enhancements. We also incurred an additional $0.7 million in restructuring costs primarily related to one-time termination benefits and ongoing benefit arrangements, $0.6 million of which were paid as of June 30, 2024.

In total, we recognized restructuring costs of $8.9 million during the six months ended June 30, 2024. The activities related to these restructurings were primarily completed as of June 30, 2024.