What is National Pension System? The Central Government has introduced the Defined Contribution based Pension System known as the National Pension System (NPS) or Contributory Pension System (CPS) (but is popularly known as New Pension System/Scheme) replacing the existing system of Defined Benefit Pension with effect from January 01, 2004. This is the 1st Part of the our upcoming 3 Parts Series on NPS.