Background. Medication treatment of Opioid Use Disorder (MOUD) saves lives and is increasingly delivered virtually. Currently, 60% of VA outpatient addiction treatment occurs over video. The pandemic accelerated this trend, but it will be sustained through multiple VA policies. However, toxicology testing, a major component of MOUD care, currently requires in-person visits. A process for virtual point-of-care toxicology testing is needed. Significance. In current virtual MOUD care, toxicology testing is either not completed or requires in-person urine testing, which is inconvenient and stigmatizing. A process for virtual point-of-care testing, which mitigates these barriers, will be developed through this research. Such as process will be more acceptable, facilitate patient-centered care, and decrease stigma, improving MOUD utilization and patient outcomes. This research will directly address VA stated goals to “Improve MOUD implementation” and “Understand how to address stigma.” Innovation. MOUD care, which incorporates (1) virtual toxicology testing, (2) patient self-testing at the point-of- care, and (3) oral-fluid test kits, is entirely novel. There has been no research on virtual point-of-care toxicology testing among Veterans. In addition, virtual toxicology testing will advance other innovative addiction treatments such as virtual contingency management. Specific Aims. This research will develop a Virtual Point-of-Care Toxicology Testing Process for VA. AIM 1 (Pre-Pilot) will design and iteratively modify a Virtual Toxicology Testing Process, which uses oral fluid test kits. AIM 2 (Pilot Trial) will evaluate the feasibility, acceptability, and proximal effects of the process by evaluating provider and patient testing uptake, qualitative feedback, and health service use. AIM 3 (Scale-up) will (1) prepare a Virtual Point-of-Care Toxicology Testing Toolkit and (2) operationalize testing for a future multi-site randomized trial. Methodology. Mixed-methods will be used to develop and evaluate the testing process, which will use an oral- fluid test for common drugs of abuse. Patients will self-administer the test during virtual MOUD visits and assess results with providers. In the pre-pilot phase, stakeholder groups of VA-wide clinical/laboratory leaders, providers, and patients will design and iteratively modify the process. In the pilot phase, a single-arm mixed- methods pilot trial will evaluate the process among patients and providers at two VA facilities. Feasibility will be evaluated by examining process uptake. Acceptability will be evaluated through semi-structured interviews with patients and providers based on Consolidated Framework for Implementation Research (CFIR) constructs. Health service use will be evaluated by analyzing data on patient characteristics, test utilization, and treatment contacts extracted from the electronic medical record. In the scale-up phase, the Virtual Point-of-Care Toxicology Testing Process will be summari...