The National Pension System (NPS) operates on a two-tiered account structure under a single Permanent Retirement Account Number (PRAN). Regulated by the Pension Fund Regulatory and Development Authority (PFRDA), NPS offers subscribers the ability to build a locked-in, tax-efficient retirement corpus while simultaneously maintaining a flexible, liquid investment pool. Understanding the distinction between Tier I and Tier II accounts helps investors structure their short-term and long-term financial goals.