A 412(i) is a defined benefit plan. A defined benefit plan "defines" how much money or "benefit" you will receive at retirement (IRS maximums apply). To determine this amount, a plan must calculate how much you need to contribute (at an applicable rate of return) to reach that retirement goal. Therefore, with a 412(i) you are allowed to contribute larger amounts to ensure proper funding for your future defined benefit. These larger contribution amounts are calculated using the guaranteed interest rate within the insurance polices, allowing for much higher plan contributions than a standard defined benefit plan will allow.