This guidebook provides the necessary information for conducting a Technology Readiness Level (TRL) Assessment. TRL Assessments are a tool for determining the maturity of technologies and identifying next steps in the research process. This guidebook offers background on the TRL Scale, walks through every aspect of preparing for and conducting a TRL Assessment, and provides helpful tools and tips throughout. TRL Assessments are flexible evaluation tools and can be used in a variety of settings to fit the needs of the agency conducting them. Having a simple mechanism to determine and communicate technology maturity improves research outcomes and program management.