Context: The issue of insurance deductions is one of the major problems that lead to the shortage of financial resources in hospitals. The present study was conducted to review the root causes of insurance deductions and propose solutions to reduce them in Iranian hospitals. Methods: This was a scoping review of the literature on health insurance deductions in hospitals in Iran within 2000 - 2023 to synthesize the findings of original Persian and English studies that focused on the causes of deductions and propose strategies to reduce them in Iranian hospitals. The relevant concepts and terminology in health insurance deductions were found through medical subject headings (MeSH). The articles were screened based on the preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist. Analysis of research data (text of the articles) was carried out by the content analysis technique in MAXQDA software (version 10). Results: A total of 1121 publications were identified, of which 41 publications met the inclusion criteria and were reviewed. Based on the present analysis, most studies (61%) were published within 2016 - 2020, 12.2% of the included studies were qualitative, and 48.8% were performed in hospitals. Finally, 46 causes of deductions and 35 solutions to reduce insurance deductions were extracted. The leading causes of deductions were associated with service delivery, service registration, sending documents, and conversion of services into revenue. The most important causes of deductions in dimensions of providing and registering services were a lack of familiarity of service providers with insurance rules and regulations, coding and relative value book, extravagance and motivation of providers to earn more revenue, and lack of strong infrastructure to register services. Furthermore, strategies for reducing health insurance deductions were categorized into three groups, namely meta (ministries of health), macro (universities), and mezzo (hospitals). The top strategies to reduce health insurance deductibles were associated with several dimensions, such as providers, process modification, policy reform, and infrastructure modification. The most important strategies to reduce deductions in these four dimensions were teaching the documentation principles to all medical staff, familiarizing physicians with insurance laws and correct coding, continuous interaction between insurance companies and hospitals, and revisions in the repayment system. Conclusions: The causes of deductions could be determined through several dimensions. To manage and reduce the number of deductions, these causes should be carefully examined in the dimensions of service delivery, service registration, and document regulation and audit, and each hospital should use relevant strategies according to the weak points. However, solving the issue of deductions is not only related to hospitals; it is necessary for policymakers and health managers in the ministries of health, universities of medical sciences, and health insurance organizations to adopt necessary policies, especially in the field of hospital information management, to reduce deductions. According to the presented topics, the efficiency of hospitals and, ultimately, the quality of medical care can improve through a correct and more accurate understanding of the causes of deficits. It also prevents the waste of financial resources in hospitals, which is the main support in providing services and survival.