Online Yoga vs Acceptance and Commitment Therapy for Treating Chronic Musculoskeletal Pain

Inclusion Criteria:

* Veteran of the United States Armed Forces ≥ 18 years old
* Chronic pain \> 6 months related to at least one musculoskeletal pain-related diagnosis indicated by an ICD-9 or -10 code
* Minimum pain intensity at screening ≥4 on a 0-10 using the Defense and Veterans Pain Rating Scale (DVPRS)
* Not begun new pain treatments or medications in the past month
* Stable medication regimen for at least 4 weeks prior to entry to the study
* English literacy
* Internet connection at home

Exclusion Criteria:

* Participation in another clinical trial, unless given prior authorization from both our research team and that of the other study
* Back surgery within the last 12 months
* Back pain potentially attributed to a specific known condition
* Baseline pain \<4 or ≥9 on a 0-10 Numeric Rating Scale
* Unstable, serious coexisting medical illness, mental illness or psychiatric conditions
* Attended or practiced yoga ≥ 1 x in the past 12 months
* Current suicidal intent or plan
* Has received ACT in the past