Update March 7, 2018:
IMBA’s Instructor Certification Program (ICP) has transitioned to the Bike Instructor Certification Program (BICP) and is no longer part of IMBA. It’s still led by Shaums March, but under a new non-profit organization. They’ve also reconfigured their courses/certifications with new pricing to: Ride Leader, Level 1, Level 2, Level 1-2 Combo, Level 3. And they’ve added recertification, prep, and refresher courses, too. Their new logo:
I’ve not updated the links or information in the blog post below.
This spring (2016) I’ve gotten certified as both an IMBA ICP Level 2 and PMBI Level 1 mountain bike instructor (blog posts with photos here and here). The competing certifications are similar in that they’re designed to equip one with the ability to instruct beginner and intermediate-level riders in basic skills. (IMBA’s ICP Level 1 is a Ride Guide course; PMBI’s Ride Guide course doesn’t use a Level number.)
I wasn’t planning to take either one this spring as IMBA wasn’t offering a Level 2 course locally and PMBI’s Level 1 course at Spirit Mountain in Duluth sold out quickly. But I got lucky.