This bill, titled the "Biosimilar Red Tape Elimination Act," aims to significantly streamline the regulatory pathway for biosimilar biological products. It primarily achieves this by amending the Public Health Service Act to revise the requirements for determining interchangeability between a biosimilar and its reference product. The legislation seeks to accelerate patient access to these cost-effective medications. A central provision of the bill is that a biological product licensed as biosimilar will now be deemed interchangeable with its reference product upon licensure, removing the previous requirement for a separate interchangeability determination. This deemed interchangeability takes effect either upon licensure for products approved after a 60-day transition period, or on the transition date for products licensed before it. However, this automatic interchangeability is delayed if another biosimilar relying on the same reference product currently holds an unexpired first interchangeable exclusivity period. To ensure fairness, the bill explicitly preserves any existing first interchangeable exclusivity periods for biological products licensed before the act's enactment. Furthermore, it mandates that the Secretary of Health and Human Services update and issue new guidance within 18 months to reflect these changes, including revising or revoking specific guidance documents related to interchangeability. The legislation clarifies that these amendments do not alter the fundamental standard or information required for biosimilar licensure, only the process for interchangeability.