This article critically examines the corporate production, archival politics, and socio‐legal dimensions of Corporate Mortality Files (CMFs), the largest corporate archive developed by International Business Machine's Corporation (IBM) to systematically document industrial exposures and occupational health outcomes for electronics workers. I first provide a history of IBM's CMF project, which amounts to a comprehensive mortality record for IBM employees over the past 40 years. Next, I explore a recent case in Endicott, New York, birthplace of IBM, where the U.S. National Institute for Occupational Safety and Health (NIOSH) studied IBM's CMFs for workers at IBM's former Endicott plant. Tracking the production of the IBM CMF, the strategic avoidance of this source of Big Data as evidence for determining a recent legal settlement, alongside local critiques of the IBM CMF project, the article develops what I call “late industrial necropolitics.” This article is protected by copyright. All rights reserved