Background: More than 70,000 people died in the United States in 2017 as a result of a drug-related overdose. Among those who died, 46,600 died from the use of an opioid. While several policies have been enacted to reduce the harms caused by drug use, by increasing access to substance use disorder (SUD) treatment, little is known about how these policies have transformed the SUD treatment industry. Aims: (1) determine the effectiveness of the ACA at addressing SUD related issues using a policy analysis approach (2) qualitatively investigate how changes in healthcare policy have negatively impacted substance use treatment services and caused abuses in the treatment industry, and (3) quantitatively analyze factors associated with non-fatal opioid overdose among a suburban/exurban opioid-using population in Southern California. Methods: Professionals in the addiction field (Chapter 2 and 3; n = 20), people who misuse opioids (PWMO) who attended SUD treatment (Chapter 3; n = 20), and PWMO (Chapter 4; n = 355) were interviewed. Thematic data analysis was conducted in Chapter 2, a grounded theory approach to data analysis was conducted in Chapter 3, and a logisti regression analysis was conducted on non-fatal opioid overdose and its association with SUD treatment in Chapter 4. Results: In Chapter 2, five themes were reported: 1) effectiveness of the ACA for the treatment of an SUD, 2) unintended effects of the policy, 3) effect of the policy on different groups, 4) medication-assisted treatment, 5) and solution to the problem. In Chapter 3, four themes emerged:1) patient brokering, 2) financial enticements, 3) drug use to get into treatment and, 4) opioid overdose risk. In Chapter 4, first using an opioid drug by non-oral methods, methadone detox, buprenorphine detox, and 12 step attendance were found to be positively associated with lifetime non-fatal opioid overdose. Conclusions: While the ACA has increased access to SUD treatment, the unethical and sometimes illegal practices in the SUD treatment environment may have decreased its effectiveness. Furthermore, some types of SUD treatment may increase the risk of an overdose. This dissertation is an important contribution to the field because it will inform future policy decisions.