Many organizations hire individual contractors as well as people from consulting companies to help them staff their Disciplined Agile teams.
This page describes suggested criteria for hiring people with appropriate Disciplined Agile (DA) skills.
The minimum is for candidates to have earned their Certified Disciplined Agilist (CDA). However, because the CDA is only an indication that people have knowledge of DA it is recommended that candidates have earned their Certified Disciplined Agile Practitioner (CDAP). Someone with their CDAP has a deeper understanding of Disciplined Agile and at least two years of experience on agile delivery teams.
It is possible for someone with their CDAP to coach a team, often with the guidance of a more senior coach. However, the reality is that you want people who have earned the Certified Disciplined Agile Coach (CDAC) designation.
Read our post on the types of agile coaches you may need, and the skills we feel an enterprise coach should have: The Agile Enterprise Coach
Any DA trainer should have earned their Certified Disciplined Agile Instructor (CDAI) so that they may teach DA workshops.