13 CFR § 120.801 - How a 504 Project is financed.
(a) One or more small businesses may apply for 504 financing through a CDC serving the area where the 504 Project is located. SBA issues a loan number if it agrees to guarantee part of the funding for a Project.
(b) Usually, a Project requires interim financing from an interim lender (often the same lender that later provides a portion of the permanent financing).
(c) Generally, permanent financing of the Project consists of:
(1) A contribution by the small business in an amount of at least 10 percent of the Project costs;
(2) A loan made with the proceeds of a CDC Debenture for up to 40 percent of the Project costs and certain administrative costs, collateralized by a second lien on the Project Property; and
(3) A Third Party Loan comprising the balance of the financing, collateralized by a first lien on the Project property (see § 120.920).
(d) The Debenture is guaranteed 100 percent by SBA (with the full faith and credit of the United States), and sold to Underwriters who form Debenture Pools. Investors purchase interests in Debenture Pools and receive Certificates representing ownership of all or part of a Debenture Pool. SBA and CDCs use various agents to facilitate the sale and service of the Certificates and the orderly flow of funds among the parties.