Healthcare quality managers and researchers often need to identify specific healthcare events from administrative data. In this study, we examined whether Veterans Health Administration (VHA) clinic stop and bed section codes are reliable indicators of substance use disorder (SUD) treatment as documented in clinical progress notes. For outpatient records with a progress note, SUD clinic stop code, SUD diagnosis code, and mental health procedure code, we found chart documentation of SUD care in 92.0% of 601 records: 82.5% of 372 records with a SUD clinic stop code and SUD diagnosis code but no mental health procedure code, 21.9% of 379 records with a SUD clinic stop code and mental health procedure code but no SUD diagnosis code, and 55.3% of 318 records with a SUD clinic stop code but no SUD diagnosis or mental health procedure code. For inpatient stays with a SUD bed section code and a progress note, we found chart documentation of SUD care in 99.0% of 699 records accompanied by a SUD diagnosis but 0% of 39 records without a SUD diagnosis. These results provide validity evidence and caveats to researchers and VHA quality managers who might use SUD specialty location codes as indicators of SUD specialty care.