Professional coaching has extended from the C-Suite's upper echelons to the mainstream and emerged as a viable customizable human capital management initiative democratizing professional coaching (Colletta, 2020; Joo, 2005; Kampa-Kokesch & Anderson, 2001). Experienced professional coaches often refer to "coachability," which is a component of a successful coaching engagement. However, the term needs to be researched and expanded upon in the current professional coaching literature. Current research on coachability follows within sports, sales performance, entrepreneurship, and workplace/employee.This mixed-method (survey and semi-structured interviews) exploratory study identified that professional development coachability exists and possesses identified specific associated attributes. This understanding was essential in establishing a professional development coachability construct, definition, and profile. Professional development coachability (PDC) is a complex system or construct that intersects in personal traits, coach and coachee dynamics, and social, environmental, and psychological components. PDC has been defined as an amalgamation of external and internal factors that align at a specific moment under specific circumstances. It is complex, malleable, and impacted by the circumstances and conditions in and around the coaching engagement. Study 1 (survey, n=209) identified the internal/intrinsic behavioral factors that influenced professional development coachability through the eyes of experienced professional coaches. This study resulted in a five-item coachability profile established by quantitative [(N of Items=5) Cronbach's Alpha .75, Cronbach's Alpha Based on Standardized Items of 0.76 and a valid n=40] and supported qualitatively. Study 2 (semi-structured interviews/mini survey, n=44) was conducted with experienced professional coaches, a subset of the survey participants, almost one year after the initial Study 1. Based on the results of the five-item survey in Study 2, the five-attributes profile from Study 1 was supported quantitatively by Study 2 [(N of Items=5) Cronbach's Alpha .70, Cronbach's Alpha Based on Standardized Items of .70 and a valid n=44]. The profile presents critical attributes or factors that a client/coachee intrinsically brings (perception of coachability) to support the coaching process. Subsequently, the five attributes/factors profile and identified external factors inductively derived from Study 2 set the foundation for an initial definition and theoretical framework for professional development coachability. Keywords: coachability, executive coaching, professional coaches, leadership development, definition, personal and professional development, internal and external factors, theoretical framework, exploratory mixed-method / Business Administration/Human Resource Management