Here's a link to a 3 part course about the SBA's HUBZone program.
1. What are HUBZone designations, how they are determined, where they are located and how to find them. https://www.sba.gov/course/hubzone-mini-primer-1/
2. HUBZone Eligibility Requirements, including principal office, employee and residency requirements. https://www.sba.gov/course/hubzone-mini-primer-2/
3. Understanding HUBZone status protests. https://www.sba.gov/course/hubzone-mini-primer-3/
