The Patient Protection and Affordable Care Act (ACA) established a new regulatory pathway for a class of drugs known as biosimilars. Biosimilars, also known as “follow on biologics,” are medicines that are similar to, but not exact copies of, biologically derived drugs. Biologically derived drugs are called “biologics.” A is a drug or vaccine made from a living organism. Biologics are very complex and extremely biologic1 difficult to manufacture. Unlike chemically derived drugs that can have generic versions, biosimilars are not generic versions of the original biologic they seek to mimic. Biosimilars are only similar to the original biologic and not an exact replication. The upside for biosimilars is that they may be less expensive than the biologic they mimic and thus more patients could have access to these less expensive drugs.