Abstract Background The reimbursement for expensive medicines poses a growing challenge to healthcare worldwide. In order to increase its control over the costs of medicines, the Dutch government introduced the Coverage Lock (CL) policy in 2015. The CL postpones decisions regarding reimbursement of expensive medicines until detailed advice on i.e., cost-effectiveness has been given. The CL has been in place for six years, has raised many questions and concerns, but currently, no evaluation is known to the authors. A better understanding of the effects of the CL on all stakeholders involved may contribute to reflections on the CL process and help find ways to improve it. An evaluation of Dutch policy will also be relevant for other countries that aim to optimize reimbursement procedures for expensive treatments. To perform this evaluation, we focused on the CL procedure for the medicine nusinersen. Nusinersen is the first treatment for spinal muscular atrophy (SMA). Following EMA approval in May 2017, it was ...