This study focuses on administrative capacity and domestic EU-coordination structures in new member states. It analyzes data from 65 semi-structured interviews with Brussels officials and confronts them with primary data and review of the existing research on EU member states. It is argued that the Central and Eastern European states in the EU are predominantly influenced by the length of their membership, their size and their human resources management in EU affairs. The length of the membership influences member states' knowledge about inner workings of the EU and their ability to build and sustain institutional relations and networks with and within EU institutions. Being mostly small countries, new member states (NMS) have used prioritization of issues and EU presidency as a contra-strategy, but have had only limited success in uploading their preferences to the EU level so far. In the personnel policy, several NMS revised their conditionality-influenced legislation on civil service after becoming EU members, which seems to have influence on a high level of turnover in EU bureaucratic positions, and is directly connected to NMS' ability to establish and defend their national positions in the EU affairs.