PurposeThis paper examines the sluggish adjustment of deposit interest rate categories with response to policy rate changes in a developing economy.Design/methodology/approachSymmetric and asymmetric error correction models (ECMs) are employed to test the pass-through effect and adjustment speed of deposit rates when above or below their equilibrium levels.FindingsThe findings reveal an incomplete pass-through effect in both the short run and long run while mixed results of symmetric and asymmetric adjustment speed across the different deposit rate categories are observed. Collusive pricing arrangement behavior is supported by deposit rate categories that adjust more rigidly upwards than downwards, while negative customer reaction behavior is supported by deposit rate categories that adjust more rigidly downwards than upwards.Practical implicationsEven though the findings indicate an aspect of increased responsiveness over the period, the sluggish adjustment of deposit rates imply that monetary policy is still ineffective and not uniform across the different deposit rate categories.Originality/valueTo the best of the authors' knowledge, this is the first study to empirically examine both symmetric and asymmetric adjustment behavior of deposit interest rate categories in Kenya. The findings are key to policy makers as they provide insights on how long it takes to adjust different deposit rate categories to monetary policy decisions. In addition, the behavior of deposit rates partly explains why interest rates capping was imposed in Kenya in 2016.