This chapter examines Bulgaria’s integration into the European Union, highlighting both the economic benefits and persistent challenges faced since accession in 2007. It contextualizes Bulgaria’s EU membership within the broader framework of regional economic integration, assessing how EU policies have influenced the country’s economic trajectory. The chapter explores multiple dimensions of integration, including market access, regulatory alignment, capital flows, labor market dynamics, and fiscal transfers. Bulgaria has made significant progress in GDP growth, foreign direct investment, and infrastructure development due to EU membership. The chapter notes improvements in trade volumes, enhanced legal frameworks, and increased fiscal support through cohesion and structural funds. However, challenges such as income inequality, regional disparities, governance deficiencies, and demographic decline persist. The chapter critically analyzes how Bulgaria’s reliance on foreign investments and the structural limitations of EU funds have constrained long-term economic convergence. Furthermore, it addresses the socioeconomic consequences of emigration and brain drain. Through a comparative approach, the chapter evaluates Bulgaria’s performance relative to other EU and non-EU countries, offering insights into the complex and multifaceted impacts of regional economic integration. It underscores the need for strategic domestic reforms to fully leverage EU membership benefits and ensure inclusive, sustainable growth.