To test these hypotheses, 766 adults with opioid-treated CLBP from Madison, WI, Boston, MA, and Salt Lake City, will be randomly assigned into one of two 8-week treatment groups: MM (383 participants) that will receive the MM training or CBT (383 participants) that will receive the CBT training. The effectiveness of MM versus CBT will be assessed over a 12-month period with patient-reported measures, recommended by experts and endorsed by our stakeholder partners, including patients with opioid-treated CLBP, their families and clinicians.