Agile Coach vs Scrum Master

While in the Agile community and in client’s companies, the two roles are often seen as distinct, there is significant overlap between the two.

When we look at the different stances traditionally associated with a Scrum Master, for instance at Scrum.org we find:

Name	Explanation
Servant Leader	whose focus is on the needs of the team members and those they serve (the customer), with the goal of achieving results in line with the organization’s values, principles, and business objectives.
Facilitator	by setting the stage and providing clear boundaries in which the team can collaborate.
Coach	coaching the individual with a focus on mindset and behavior, the team in continuous improvement and the organization in truly collaborating with the Scrum Team.
Manager	responsible for managing impediments, eliminating waste, managing the process, managing the team’s health, managing the boundaries of self‐organization, and managing the culture.
Mentor	that transfers agile knowledge and experience to the team.
Teacher	to ensure Scrum and other relevant methods are understood and enacted.
Impediment Remover	solving blocking issues to the team’s progress, taking into account the self‐organizing capabilities of the Development Team.
Change Agent	to enable a culture in which Scrum Teams can flourish.

and we compare them with the competences expected of an Agile Coach, for instance from this summary of Lyssa Adkins' traditional coaching diagram.

Name	Explanation
The Agile-Lean Practitioner	Ability to learn and deeply understand Agile frameworks and Lean principles, not only at the level of practices, but also at the level of the principles and values that underlie the practices enabling appropriate application as well as innovation.
Professional Coaching	Ability to act as a coach, with the client’s interest determining the direction, rather than the coach’s expertise or opinion.
Facilitating	Neutral process holder that guides the individual’s, team’s, or organization’s process of discovery, holding to their purpose and definition of success.
Mentoring	Ability to impart one’s experience, knowledge and guidance to help grow another in the same or similar knowledge domains.
Teaching	Ability to offer the right knowledge, at the right time, taught in the right way, so that individuals, teams and organizations metabolize the knowledge for their best benefit.
Technical Mastery	Ability to get your hands dirty architecting, designing, coding, test engineering, or performing some other technical practice, with a focus on promoting technical craftsmanship through example and teaching-by-doing. And, expertise in agile scaling patterns or structures.
Business Mastery	Ability to apply business strategy and management frameworks to employ agile as a competitive business advantage such as Lean Start-Up, product innovation techniques, flow-based business process management approaches, and other techniques that relate to innovating in the business domain.
Transformation Mastery	Ability to facilitate, catalyze and (as appropriate) lead organizational change and transformation. This area draws on change management, organization culture, organization development, systems thinking, and other behavioral sciences.

Given such overlap, why do so many people see them as dissociated?

My impression is that the terms and roles we see today are still being refined. We see a lot of Scrum Masters coming from a technical track, whereas often Agile Coaches come from a Soft Skills background, many employers hiring traditional People Coaches as Agile Coaches. Neither is bad in itself, but I believe both sides will have to absorb some of their counterpart's toolkit. And while that happens, the terminology will evolve to reflect the changing understanding of the roles.

Further information:

If your curiosity is piqued and you wish to look further into this topic, I've gathered some information below:

Articles:

Scrum Master role description

Coaching diagram