Aim: In active relapsing remitting multiple sclerosis (RRMS) patients requiring second-line treatment, the Dutch National Health Care Institute (ZiN) has not stated a preference for either alemtuzumab, fingolimod, or natalizumab. The aim was to give healthcare decision-makers insight into the differences in cost accumulation over time between alemtuzumab—with a unique, non-continuous treatment schedule—and fingolimod and natalizumab for second-line treatment of active RRMS patients in the Netherlands. Methods: In line with ZiN’s assessment, a cost-minimization analysis was performed from a Dutch healthcare perspective over a 5-year time horizon. Resource use was derived from hospital protocols and summaries of product characteristics, and validated by two MS specialists. Unit costs were based on national tariffs and guidelines. Robustness of the base case results was verified with multiple sensitivity and scenario analyses. Results: Alemtuzumab results in cost savings compared to fingolimod and natalizumab from, respectively, 3.3 and 2.8 years since treatment initiation onwards. At 5 years, total discounted costs per patient of alemtuzumab were €79,717, followed by fingolimod with €110,044 and natalizumab with €122,238, resulting in cost savings of €30,327 and €42,522 for alemtuzumab compared to fingolimod and natalizumab, respectively. Key drivers of the model are drug acquisition costs and the proportions of patients that do not require further alemtuzumab treatment after either two, three, or four courses. Limitations: No treatment discontinuation and associated switching between treatments were incorporated. Consequences of JC virus seropositivity while continuing natalizumab treatment (e.g. additional monitoring) were omitted from the base case. Conclusion: The current cost-minimization analysis demonstrates that, from the Dutch healthcare perspective, treating active RRMS patients with alemtuzumab results in cost savings compared to second-line alternatives fingolimod and natalizumab from ∼3 years since treatment initiation onwards. After 5 years, alemtuzumab’s cost savings are estimated at €30k compared to fingolimod and €43k compared to natalizumab.