We live in a time of unprecedented human mobility. People move within and between countries for work, including those engaged in agricultural work, fisherfolk, miners, pastoralists, and others. Rural to urban migrations are accelerating, as is displacement due to political upheaval, violence, climate and weather emergencies, and trafficking for sexual exploitation or forced labor. An estimated 1 billion people are migrants or on the move in 2023, and while most of this movement is voluntary, the number of refugees and internally displaced people is the highest in almost a century.

Migration and mobility are social determinants of health and can be a barrier to prevention, testing, and treatment services even under the best of circumstances. Access and continuity can be challenging, priorities may be more focused on immediate survival, and there can be legal, financial, linguistic, and cultural barriers to accessing health services.

Migrants, mobile and displaced people are considered key and vulnerable populations in many settings. Migration does not automatically lead to higher HIV risk or prevalence and making that assumption can lead to stigma and discrimination. However, some migrant and mobile populations are more vulnerable to HIV and encounter more barriers to testing, treatment, and services throughout the HIV cascade.

Differentiated service delivery for mobile populations often includes:

• Involvement of affected communities in the design, delivery, and evaluation of HIV services
• Multi-month dispensing of HIV and other medications
• Mobile health / digital tools
• The use of biometrics, with careful attention to privacy and security
• Task-shifting, decentralization, and redundancy to increase the resilience of HIV services during emergencies
• Planning for emergencies
• Decentralized commodity stockpiles
• Training and mentorship of health workers
• Improved data management and tools