The SF424 Application Guide for NIH and Other PHS Agencies stipulates that the NIH has a preference for biosketches to appear in alphabetical order. However, alphabetical order is not a requirement. As the PD/PI, it is important to keep in mind that peer-reviewers will see biosketches in the order they are presented within your submission. When determining the best order, you should give consideration to the role each individual has on the project and how their expertise contributes to the bigger picture you are trying to create, which is to demonstrate to reviewers that the research team’s collective strengths are uniquely suited to address the proposed problem.