General internal medicine is a crucial element in healthcare systems. Understanding how many people are and will be working in this field is important to maintain and improve quality for patients in healthcare systems. This can provide a basis for political decisions. We conducted a cross-sectional study to analyse the current and future workforce of generalists (general practitioners and internists in hospitals) in Switzerland. The Swiss Society of General Internal Medicine (SSGIM) distributed a survey to all members. Respondents were asked about their current average workload in 2023 and planned workload in 2033. The responses were used to calculate full-time equivalent (FTE) for the current and future workforce of generalists and to extrapolate FTE for all active SSGIM members. To model the demand by 2033, we derived different scenarios. Of all 6,232 active SSGIM members, 2,030 (33%) participated: 46% female, 25% (largest age group) 56-65 years old, 19% still in postgraduate training. The average workload in 2023 was 78% for female and 87% for male generalists; the FTE extrapolated to all active SSGIM members in 2023 was 5,246. By 2033, 1,935 FTEs (36%) will retire, 502 FTEs (10%) will reduce their workload, 116 FTEs (2%) will increase their workload and 2,800 FTEs (53%) will remain in the workforce with the same workload as in 2023. To maintain the same workforce as in 2023, 2,321 new FTEs (44%) will be needed by 2033. To fill this gap of 232 FTE new generalists per year, we modelled different scenarios with assumptions of interest, workload, migration and dropouts. Within only one decade, 44% of the current workforce of generalists will disappear, mainly due to retirement and decreased workload. To fill this gap, various scenarios need to be incorporated. Politicians are called upon to create the political framework to create attractive training and working conditions for generalists to address the future demand for healthcare services.