In March 2020, insulins were transitioned from being regulated as drugs to being regulated as biological products. This transition allows for the introduction of biosimilars, which are highly similar to, and have no clinically meaningful differences from, their reference biological medication. To facilitate pharmacovigilance, an analysis was conducted to characterize how insulin was captured in electronic healthcare data sources, specifically via National Drug Codes (NDC) or Healthcare Common Procedure Coding System (HCPCS) codes. This analysis demonstrated that over 98% of the 107 million insulin claims in Sentinel between 2013 and 2018 were identified using NDC codes, supporting the use of NDCs to identify insulin exposure in drug safety studies using electronic healthcare data. Having a variety of different tools to identify products for pharmacovigilance is of high value. We have demonstrated that a large fraction of insulin use in Sentinel can be identified using NDCs. That, in addition to other identifiers, supports effective pharmacovigilance.