A Guaranteed Lifetime Income rider is an optional enhancement added to an annuity contract that ensures the annuity owner receives a predetermined stream of income for life, regardless of market performance or whether the underlying account value eventually falls to zero. The rider typically allows for an accumulation period where a benefit base grows, often via a roll-up rate or bonus, and when income begins, a payout rate is applied to that benefit base to determine annual or periodic payments. While the rider provides lifetime income, it comes with trade-offs, typically including a fee and reduced liquidity and specific rules regarding withdrawals, activation age, and contract terms.