The National Pension System (NPS) is a voluntary, long-term retirement savings scheme in India. It is regulated and administered by the Pension Fund Regulatory and Development Authority (PFRDA). NPS was initially introduced for government employees but was later extended to all citizens of India, including both the organized and unorganized sectors.

Here are some key features of the National Pension System (NPS):

1. Tiered Structure: NPS consists of two tiers: Tier I and Tier II.

   • Tier I: This is the primary pension account with restrictions on withdrawals. It is designed to provide retirement income.
   • Tier II: This is an optional account that is more like a savings or investment account. It allows for easier withdrawals and doesn't have the same restrictions as Tier I.

2. Voluntary and Portable: NPS is open to all Indian citizens, including Non-Resident Indians (NRIs). It's a portable scheme, which means you can continue contributing to it even if you change jobs or locations.

3. Professional Fund Management: NPS offers a choice of pension fund managers and investment options. You can select from a range of asset classes, including equities, government bonds, and corporate bonds. This allows you to build a diversified portfolio.

4. Regulated by PFRDA: The Pension Fund Regulatory and Development Authority oversees and regulates NPS to ensure transparency, security, and accountability.

5. Tax Benefits: NPS provides tax benefits under various sections of the Income Tax Act. Contributions up to a certain limit are deductible from taxable income. Additionally, there are tax exemptions on lump-sum withdrawals and annuities.

6. Flexible Contributions: You can decide the frequency and amount of contributions, and you can increase or decrease them as per your financial situation. However, there are limits on the minimum and maximum contributions.

7. Retirement Benefits: At the time of retirement (after the age of 60), you can withdraw a portion of the corpus as a lump sum, and the remaining amount must be used to purchase an annuity, which provides regular pension income.

8. Partial Withdrawals: NPS allows for partial withdrawals for specific purposes like medical treatment, education, and home purchase, subject to certain conditions.

9. Annuity Options: Upon retirement, you can use the accumulated corpus to purchase an annuity plan from an empaneled insurance provider. Various annuity options are available, including a life annuity and joint-life annuity.

NPS offers individuals a structured way to save for their retirement and enjoy tax benefits in the process. It combines elements of market-linked returns and regular pension income. It's essential to understand the investment choices, fees, and the maturity or withdrawal options before enrolling in NPS, as these aspects can vary depending on your preferences and risk tolerance.