Planned Amortization Class

Planned amortization class (PAC)

(1) The class of CMO that has the most stable cash flows and the lowest prepayment risk of any class of CMO. Because of a stable cash flow, it is considered the least risky CMO. (2) A CMO bond class that stipulates cash flow contributions to a sinking fund. A PAC directs principal payments to the sinking fund on a priority basis in accordance with a predetermined payment schedule, with prior claim to the cash flows before other CMO classes. Similarly, cash flows received by the trust in excess of the sinking fund requirement are also allocated to other bond classes. The prepayment experience of the PAC is therefore very stable over a wide range of prepayment experience.

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PAC Bond

A collateralized mortgage obligation that seeks to protect investors from prepayment risk. PACs do this by setting a schedule of payments; if prepayments of the underlying mortgages exceed a certain rate, the life of the PAC is shortened. If they fall below a certain rate, the life of the tranche is extended. This helps protect investors in case the holders of the underlying mortgages do not pay off their mortgages as expected.

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planned amortization class (PAC)

A type of collateralized mortgage obligation with a predetermined principal paydown schedule that provides investors with greater cash-flow certainty and a more specific average life. The greater payment certainty comes at the expense of a lower yield to investors.