Government regulation of health professionals is believed to ensure the efficacy and expertise of practitioners for and on behalf of patients. Certification and licensing are two common means to do so, legalizing a physician to practice medicine. However, ethnography from Ho Chi Minh City (HCMC) suggests that in corrupt socioeconomic environments, certification and licensing can alternatively produce a trade in legitimacy. Drawing on participant observations during 15 months of fieldwork with 25 medical acupuncturists in private practice in HCMC, southern Vietnam, and their patients, I argue that everyday practices of corruption and the importance of personal networks meant that legality, efficacy, and expertise separated. Certificates and licenses did not unproblematically validate expertise and efficacy. Consequently, compliance and enforcement of regulations as solutions to inadequate medical care may not achieve the effects intended.