Important Note: The above calculators are approximations because Excel does not properly compute the initial, abbreviated six-month coupon of the debenture. CSA will deliver the effective rate each month.

Effective interest rates are calculated by the Central Servicing Agent after receipt of debenture pricing provided by the Fiscal Agent every month. They are posted here as soon possible and should usually be available the day prior to funding, at the latest. Twenty and twenty five-year debentures are pooled and sold the first Thursday of the first full week of each month (beginning with and including Sunday). 10-year debentures are pooled and sold the first Thursday of the first full week of every other month (beginning with and including Sunday) starting with the January sale.

NOTE: Effective rates are posted on this site upon receipt from the CSA.


Past Effective Rate Tables

Total Pool Size and Debenture Rate

Comparative Loan Costs 

20 & 25 Year Debenture Effective Rate

If you have questions or get asked by TPLs or borrowers on how 504 Effective Interest Rates are calculated, the Fiscal Agent prepared the following presentation containing detailed information on funding a 504 loan and how the debenture and effective interest rates are determined. 

An additional resource that provides details on the funding process, "From Window to Wall Street," is available here.

How Effective Rates are Calculated

Approximate 504 Loan Rate Calculators

The following list provides tables for each month showing the 504 Effective Rates. The tables are in .pdf format and can be opened using Adobe Acrobat reader.

Click here to view the file as a PDF. 


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