Methodology for the Impact 20

The Impact 20 recognizes venture-backed and private-equity-backed startups that focus on tackling key social and environmental issues as part of their business models.

Companies are required to have at least some revenue from business operations to be considered for the list. Beyond that, candidates are evaluated on four criteria:

1. Potential Impact. How substantial is the potential impact of the company’s actions in remediating a problem or unmet need?

2. Business Viability. How likely it is that the company’s business model will ultimately be successful on a continuing operating basis, and to what extent will remediating a problem or unmet need contribute to that success?

3. Innovation and Leadership. To what degree is the company a leader in its category? How pioneering is its approach? Does the scale of its solution match the scale of the problem it is addressing?

4. Track Record. What is the company’s time frame for making a substantial impact? More credit will be given to startups that have established a track record of addressing the social or environmental concerns on which they are focused.

Companies were allowed to self-nominate, and Fortune’s editors and writers also nominated candidates. A team of Fortune editors and writers reviewed all submissions, with input from experts in the field, and determined the final list.

Contributing Writers: Maria Aspan, Scott DeCarlo, Kevin Dugan, Erika Fry, Matt Heimer, Christiaan Hetzner, Felicia Hou, Jeremy Kahn, Kylie Logan, Lucinda Shen, Anne Sraders, Jonathan Vanian