Biosimilars represent an emerging area of interest for the pharmaceutical industry. Biosimilars are essentially 'generic' versions of ‘branded’ biologics, but are not considered identical to the innovator biologic. In 2009, half of the top ten selling drugs were biologics; this proportion is expected to reach 80% by 2015. Biosimilars are seen as a cost-saving alternative to payers, and as generic drugs take over the market, manufacturers are depending on biologics to drive growth. However, they will need to consider the inherent challenges in this market. This literature review was undertaken to provide a summary of the current state of affairs with biosimilars, including a review of the recent healthcare legislation and policies in countries that already have formal guidance regarding biosimilars approval. Significant resources are required to participate in the biosimilars market, including regulatory expertise, manufacturing capabilities, and global market reach. One concern to potential market players is the uncertainty regarding the approval process for biosimilars in the United States (U.S.). The Patient Protection and Affordable Care Act (PPACA 2009) authorized the FDA to develop an abbreviated regulatory pathway for biosimilar approval but guidance has not yet been issued. It is important for the U.S. to learn from other countries. This review includes a summary of other countries' approaches to biosimilars approval. For example, since 2006, the European Medicines Agency has had extensive requirements for pre-clinical and clinical data to demonstrate quality, safety, and efficacy of the product seeking approval. Questions remain including: How will the competitive landscape look as biosimilars enter the market? What will be the comfort level with substitutability of biosimilars? Will there be patent protection for the manufacturing process? And, what will the FDA require in terms of clinical trials and other supportive data to recognize biosimilars? The literature review will address these questions and more.