Problem. Given the newness of the field, those who are assigned to teach computer science (CS) in K-12 schools need targeted professional development (PD) that supports their content and pedagogical content knowledge. Currently, a diagnostic tool does not exist to identify teacher needs, leaving teachers to self-select their PD or accept recommendations from a colleague or supervisor. Research Question. Our research question for this project was: How effective is a diagnostic tool for recommending areas of growth for teachers that are aligned with the CS Standards 2-5 for Teachers? Methodology. Our mixed-methods study included both a diagnostic tool to analyze artifacts and justifications submitted by teachers and a self-assessment instrument measuring the frequency of specific practices connected to the CSTA Standards for Teachers. In this second year of testing the revised diagnostic tool, 66 teachers participated. After we trained and oversaw 23 external reviewers to review and rate the submissions, we provided recommendations for PD aligned with the Standards. Findings. Based on feedback from the teachers, the diagnostic tool proved to be helpful in providing recommended PD for two-thirds of the teachers. The self-assessment instrument may have suffered from the Dunning-Kruger effect since many teachers rated themselves higher in all areas than in the materials that they submitted indicated. Implications. This paper provides the components of the diagnostic tool and examples of the self-assessment instrument. We detail the successes, the lessons learned, and future considerations that are needed to strengthen this diagnostic tool and self-assessment instrument in order to be more beneficial for recommending PD for teachers that are aligned with CSTA Standards for Teachers (2-5).