Central bank digital currencies (CBDCs) offer numerous advantages, but their design is crucial to avoid unintended consequences, especially for monetary policy. The issuance of an unremunerated CBDC or a wholesale CBDC does not alter the objectives or operational framework of monetary policy. However, CBDCs can have negative spillover effects on monetary policy by impacting retail, wholesale, and cross-border payments. These effects include changes in money velocity, disintermediation of bank deposits, volatility of bank reserves, currency substitution, and capital flows. Countries with banking systems dependent on small retail and demand deposits, low digital payment usage, and weak macro fundamentals are particularly vulnerable. Proposed CBDC design features like caps on holdings and non-remuneration can help mitigate disintermediation risks, but they are not sufficient. Central banks must thoroughly identify and address unintended macroeconomic risks.