This guidance describes considerations for the development and labeling of in vitro companion diagnostic devices (referred to as “companion diagnostics” herein) to support the indicated uses of multiple drug or biological oncology products, when appropriate. This guidance builds upon existing policy regarding the labeling of companion diagnostics. In a prior guidance issued in 2014, the Agency stated that if evidence is sufficient to conclude that the companion diagnostic is appropriate for use with a specific group of therapeutic products, the companion diagnostic’s intended use/indications for use should name the specific group of therapeutic products, rather than specific products. This guidance expands on the policy statement in the 2014 guidance by recommending that companion diagnostic developers consider a number of factors, including but not limited to those discussed in this guidance, when determining whether their test could be developed, or the labeling for approved companion diagnostics could be revised through a supplement, to support a broader labeling claim such as use with a specific group of oncology therapeutic products (rather than listing an individual therapeutic product(s)).