This paper examines how choice architecture shapes retirement planning decisions in India’s National Pension System (NPS) — “All Citizens Model”. The study investigates whether enrolment decisions are driven by rational economic calculations or by the system’s behavioural design. Using a qualitative approach, in-depth interviews with 15 NPS subscribers were analysed through reflexive thematic analysis via MAXQDA software. Tax incentives emerged as the dominant enrolment factor, followed by government backing, peer influence, expert management, simplified registration, and protected returns. NPS structural features operating through financial utility and trust-building mechanisms exert the strongest influence on participation. The findings confirm the effectiveness of socially oriented, expertise-based, and risk-calibrated approaches grounded in prospect theory and bounded rationality. Policymakers should integrate behavioural insights alongside traditional economic incentives in pension scheme design. This study contributes to behavioural pension economics by empirically evaluating retirement choice architecture within a major emerging market context.