This paper analyzes the impact of introducing a central bank-issued digital currency (CBDC) on the operational framework of monetary policy and the macroeconomy. The authors develop a New Keynesian model with heterogeneous banks, a frictional interbank market, and central bank facilities. The model is calibrated to replicate key features of the Eurosystem and the consolidated commercial banking sector in the euro area. The analysis predicts that CBDC adoption reduces banks' deposit funding, but this reduction has a small effect on bank lending to the real economy and aggregate investment and GDP. This is because the reduction in deposits is absorbed by a decrease in reserves at the central bank, maintaining a 'floor' system. For higher levels of CBDC adoption, the loss of deposits is compensated by increased recourse to central bank credit, transitioning to a 'corridor' system. The paper also examines the transitional dynamics, showing that a temporary surge in demand for cash occurs during the transition from a floor to a corridor system. The results suggest that the household savings' remuneration channel is more important than the operational framework channel in explaining the macroeconomic effects of CBDC.This paper analyzes the impact of introducing a central bank-issued digital currency (CBDC) on the operational framework of monetary policy and the macroeconomy. The authors develop a New Keynesian model with heterogeneous banks, a frictional interbank market, and central bank facilities. The model is calibrated to replicate key features of the Eurosystem and the consolidated commercial banking sector in the euro area. The analysis predicts that CBDC adoption reduces banks' deposit funding, but this reduction has a small effect on bank lending to the real economy and aggregate investment and GDP. This is because the reduction in deposits is absorbed by a decrease in reserves at the central bank, maintaining a 'floor' system. For higher levels of CBDC adoption, the loss of deposits is compensated by increased recourse to central bank credit, transitioning to a 'corridor' system. The paper also examines the transitional dynamics, showing that a temporary surge in demand for cash occurs during the transition from a floor to a corridor system. The results suggest that the household savings' remuneration channel is more important than the operational framework channel in explaining the macroeconomic effects of CBDC.