Carbapenems are broad-spectrum antibiotics that are losing effectiveness against infections caused by multidrug-resistant that have acquired carbapenemase genes. The New Delhi metallo--lactamase ( ) is one of the most common carbapenemases in Canada and around the globe. These genes are frequently found on conjugative plasmids, which can disseminate through horizontal gene transfer. We applied whole-genome sequencing to characterize 1,032 carbapenemase-producing isolates collected by the Canadian Nosocomial Infection Surveillance Program from 2010 to 2023. Using a combination of short-read and long-read sequencing, we obtained 226 complete and circular -encoding plasmids. Unlike other carbapenemases in Canada, we found that plasmids were very diverse; there was a lack of dominant clusters identified using MOB-suite, and clustering methods were not able to accurately predict plasmid clusters for short-read-only data. The majority of plasmids were IncF-type (69.0%, 156/226). Both and carbapenemase genes were found in 11.4% (118/1,032) of isolates, and we identified several instances of both carbapenemase genes co-harboured on the same plasmid replicon (=9). Our findings highlight that plasmid transfer has not played a major role in transmission across Canada and that long-read sequencing is essential for resolving plasmid structure and cluster membership.