A type of investment plan, often sold to military personnel, that allows an investor to accumulate shares of a mutual fund indirectly by contributing a small, fixed sum over a period of usually 10, 15, or 25 years. In exchange for these payments, the investor owns an interest in a plan trust, which invests in a mutual fund. The plan trust's sponsor makes money by charging a "creation and sales charge", also known as a "front-end load", to investors. This sales charge is as high as 50% of the first 12 months' worth of payments, making periodic payment plans a potentially expensive investment option, especially for investors who do not remain invested for the full length of the plan.

Most periodic payment plans also have an annual fee and small monthly custodial fees. As a result of these fees, investors may be able to get a better deal by purchasing mutual fund shares directly. While the low required monthly contribution may be a selling point of a periodic payment plan, some brokerage companies, whose fees may be lower than that of a periodic payment plan, will allow investors to make small monthly investments and avoid large minimum investments if they establish automatic deposits.

Also known as a "contractual plan" or "systematic investment plan".