The small business rule of two requires agencies to restrict procurements for small businesses when there is a “a reasonable expectation of obtaining offers from two or more responsible small business concerns that are competitive in terms of fair market prices, quality, and delivery.” FAR 19.502-2. Agencies often use market research to assess whether the small business rule of two is met. But what happens when an agency amends its solicitation terms after conducting market research? Can the new terms render the agency’s market research, and therefore its set-aside decision, unreasonable? In a recent decision, GAO concluded that yes, market research may be insufficient to establish a set-aside if an agency amends the solicitation’s terms.