BackgroundOn 1 January 2020, the Care and Coercion Act came into effect in the Netherlands, subjecting involuntary care to more strict regulations and monitoring. This study tested changes in recordings of involuntary care during the transitional year of 2020 and after full implementation in 2021, which coincided with the first severe test of the new regulations, when COVID‐19 lockdown measures were taken on 16 March 2020.MethodsData consisted of weekly counts of involuntary care from 1 January 2017 to 31 December 2021, taken from the care data of more than 3000 clients with intellectual disabilities and challenging behaviour of 's Heeren Loo, a large long‐term care organisation in the Netherlands. An interrupted time series design was used to compare the period under the former law with the period under the new law and to the period during and after implementation, taking into account the impact of the COVID‐19 lockdown measures on recordings of involuntary care.ResultsUnder the new act in Week 1 of 2020, a statistically significant drop occurred in involuntary care counts, after which these counts gradually decreased. The start of 2021, the year in which the act was fully implemented, showed an initial increase in counts of involuntary care, followed by a decrease (all Ps < .001). The introduction of the COVID‐19 lockdown measures did not statistically affect the weekly counts of involuntary care.ConclusionsThe decrease in registered involuntary care after the Care and Coercion Act came into effect is a first indication of the efficacy of this new law that requires careful multidisciplinary consultations around the right of clients to respect their self‐determination. Follow‐up research should examine whether the impact of the new law aligns with clients' experiences of self‐determination.