An attempt to expand health insurance coverage to ‘everybody’ on the Thai soil has been implemented for years, including the provision of a health insurance scheme for migrants living in the Thailand. HIV/AIDS is one of the major health problems of migrants that can cause public health threats to the wider Thai populations. In 2013, the Ministry of Public Health (MOPH) expanded the benefits of HIV/AIDS prevention and treatment for migrant patients in the national health insurance for migrants; however, this caused the mark up in the insurance premium. To date, part of the migrant insurance premium (300 Baht of the total 1,600 Baht) is earmarked for high cost treatment including HIV/AIDS benefit. Besides, there are still migrants who are not enrolled in the insurance. Therefore, it is imperative to explore how Thailand will cope with the HIV/AIDS problems among migrants. This study employed mixed-methods design. The study was comprised of three objectives. The first objective aimed to explore the situation of HIV/AIDS treatment among migrants through in-depth interviews with local healthcare staff and policy makers and review of the second objective used qualitative approach (in-depth interviews and focus group discussion) to investigate the viewpoints of various stakeholders on the way forward about HIV / AIDS management for migrants. The third objective employed actuarial method to estimate the premium for the HIV/AIDS benefits for migrants based on the current use and prevalence of migrants under the migrant insurance scheme. The results show that the practice of treatment for insured migrant patients with HIV/AIDS and the uninsured migrants did not show any significant difference. The However some hospitals still shouldered unpaid debt from providing care for the uninsured migrants and the reimbursement from the MOPH was not always sufficient to recoup the cost of care. A sound referral system is considered an effective mechanism to address this issue as migrants would be able to access service from the country of origin and there would be less cost burden on the Thai side. Concerning the viewpoints of the interviewees, there were a couple of ideas for the management of uninsured HIV/AIDS migrant patients. First, the uninsured migrants should not have rights to enjoy the services in Thailand. All of them need to be referred back to receive treatment in the country of origin. Second, the second idea is that the Thai healthcare providers should continue providing services for the uninsured without overly causing financial burden on the users. This idea was based on health security maxim that health status should be considered the prime concern while financing should be placed at lower priority. The results of premium estimate for HIV/AIDS benefit for migrants showed that the premium earmarked for HIV/AIDS treatment amounted to only 11.9 to 32.5 Baht per person per year—much lower than the existing premium which was set at 300 Baht per annum per capita. However, interpretation of this figure should be made with caution as the calculation did not include management cost and was based on an assumption that the migrants’ utilization rate of the care for HIV/AIDS was still low. Key policy recommendations were suggested. Firstly, the MOPH should consider using part of the left-over fund of the national migrant insurance scheme, which was initially earmarked for HIV/AIDS, to recoup the unpaid debt of the hospitals which was originated from the providing care for uninsured migrants. Secondly, the migrant insurance scheme should adjust its premium to better reflect the actual unit cost at the hospitals. Lastly, the whole course of care for HIV/AIDS management in migrants should be strengthened. This includes strengthening measures to prevent new cases alongside the treatment for existing patients.