Background: Many emergency medical services and out-of-hours systems are facing an increasing demand for primary, ambulance, and secondary care services caused by population aging and a higher prevalence of long-term and complex conditions. In order to ensure safety and efficiency for future demands, many systems are changing their dispersed healthcare services towards a more integrated care system. Therefore, an evaluation of the production and performance over time of such a unified system is desirable. Methods: This retrospective quantitative study was performed with dispatch and financial accounting data of Copenhagen Emergency Medical Services for the period 2010–2019. Copenhagen Emergency Medical Services operates both an emergency number and a medical helpline for out-of-hours services. The number of calls to the emergency number, the centralized out-of-hours medical helpline, the number of dispatches, and the annual expenditure of the system are described for both the periods before and after the major reforms. Production of the emergency number and the centralized medical helpline were analyzed separately. Results: The average number of dispatches increased from 328 per 10,000 inhabitants in 2010 to 361 per 10,000 inhabitants in 2019. The newly initiated medical helpline received 533 calls per 10,000 inhabitants in its first year and 5 years later 548 calls per 10,000 inhabitants. A cost increase of 10% was observed in the first year after the reforms, but it decreased again to 8% in the following year. Conclusions: There is a population demand for a centralized telephone access point for (semi-)emergency medical services. A more integrated EMS system is promising for a sustainable healthcare provision for a growing population with complex healthcare demands and multi-morbidities.