Constraints on the decay of 180mTa

180⁢𝑚Ta is a rare nuclear isomer whose decay has never been observed. Its remarkably long lifetime surpasses the half-lives of all other known 𝛽 and electron capture decays due to the large K-spin differences and small energy differences between the isomeric and lower-energy states. Detecting its decay presents a significant experimental challenge but could shed light on neutrino-induced nucleosynthesis mechanisms, the nature of dark matter, and K-spin violation. For this study, we repurposed the Majorana Demonstrator, an experimental search for the neutrinoless double-beta decay of 76Ge using an array of high-purity germanium detectors, to search for the decay of 180⁢𝑚Ta. More than 17 kg, the largest amount of tantalum metal ever used for such a search, was installed within the ultralow-background detector array. In this Letter, we present results from the first year of Ta data taking and provide an updated limit for the 180⁢𝑚Ta half-life on the different decay channels. With new limits up to 1.5 ×1019  yr, we improved existing limits by 1–2 orders of magnitude which are the most sensitive searches for a single 𝛽 and electron capture decay ever achieved. Over all channels, the decay can be excluded for 𝑇1/2<0.29×1018  yr.