​A lock-in period in mutual funds refers to the duration during which the invested units cannot be redeemed or withdrawn. During this time, the investor is restricted from selling or switching the mutual fund units.

Lock-in periods are typically applicable to specific categories of funds, such as:

Equity Linked Savings Schemes (ELSS): These funds have a mandatory lock-in period of 3 years, making them eligible for tax deductions under Section 80C of the Income Tax Act.

Retirement or pension-oriented mutual funds: These may have longer lock-in periods as specified in the scheme's terms.

The lock-in period ensures that investments stay intact for a minimum duration, which is often aligned with the fund’s objective, such as long-term wealth creation or tax saving. After the lock-in ends, the investor is free to redeem or switch the units.

Read more on what is an ELSS Fund and how it can give stock like returns while giving tax advantages.​