This multicenter, cluster-randomized, unblinded quality-improvement study evaluates whether home-based clinical assessment by municipal acute care teams can safely reduce hospital admissions among nursing home residents experiencing acute illness or clinical deterioration during out-of-hours periods. Participating nursing homes in the Capital Region of Denmark will be randomized to either usual care (contacting the regional medical helpline, 1813) or the intervention pathway, in which nursing home staff contact a municipal acute care team directly. The acute care team performs an on-site clinical assessment and, when needed, consults a senior physician in the hospital emergency department to establish a treatment and observation plan, which may include continued management at the nursing home under hospital responsibility. The study compares the intervention with usual care with respect to hospital admissions and mortality among nursing home residents.