The rating on Washington State Housing Finance Commission's variable-rate multifamily housing refunding revenue bonds reflects extremely strong credit enhancement of the mortgage backing the bonds through a Fannie Mae collateral agreement, and 'AAA' rated investments. Upon bond closing, Fannie Mae will provide a direct-pay credit enhancement facility. The credit facility is direct pay through which Fannie Mae will make all regularly scheduled payments of principal and interest due on the mortgage. Under this structure, the trustee is instructed to draw on Fannie Mae one day prior to each bond interest payment date. Fannie Mae then pays on each interest payment date, hence there is no lag in this structure. Fannie Mae's obligation under the credit enhancement facility is absolute and