The penal minimalist approach, as one of the new developments in penal policies, emphasizes reducing the use of prison sentences and replacing them with corrective and preventive measures. This study aims to examine the bases of the tendency to criminal minimalism in the 2019 Reduction of Penalty Sentences Act and compare it with the American legal system. The findings of the study show that the tendency to criminal minimalism is rooted in criminological perspectives such as theories of social disability, criminal psychology, restorative and Marxist justice, which emphasize the ineffectiveness of prison in reforming criminals and increasing the cycle of crime. From a criminal law perspective, the reformability of criminals, reduction of economic costs, proportionality of punishment, protection of human rights, and inefficiency of the prison system are among the foundations of this approach. In the American penal system, especially after the enactment of the Prisoner Recidivism Reduction Act (2018), minimalist policies have been pursued with a focus on reducing prison terms, improving prison conditions, implementing correctional and rehabilitation programs, and reducing socio-economic inequalities in the administration of justice. Compared to the United States, Iranian penal reforms have mainly focused on reducing custodial sentences and developing leniency institutions. The present study, which was developed using a descriptive-analytical method, shows that penal minimalism can help reduce the prison population, reduce government costs, and increase the efficiency of criminal justice. However, the successful implementation of this approach in Iran requires the development of alternative policies, effective monitoring of the implementation of non-custodial sentences, and the expansion of support and correctional programs.