The SBA 504 Debenture: How the CDC's Half of Your Loan Gets Funded and Priced

Most borrowers walk into an SBA 504 loan thinking of it as one loan. It is really three pieces stacked on top of each other, and the middle piece — the one your Certified Development Company (CDC) arranges — works unlike anything else in small-business lending. It is funded by selling a bond to the open market after you close, and its interest rate is set by that bond sale, not by your lender. If you do not understand that mechanic, the rate you end up with can feel like a surprise. It should not be.

The three-part structure of a 504 loan

The SBA 504 program is built for owner-occupied commercial real estate and long-life equipment. A typical deal is split roughly this way:

• About 50% from a bank or credit union — the first-lien, conventional piece. The bank sets its own rate and term on this part.
• Up to 40% from the CDC — the second-lien piece, funded by an SBA-guaranteed debenture. This is the part this article is about.
• At least 10% from you — your equity injection. The SBA requires more — 15% if the business is a startup (generally under two years old) or the property is a “special-use” building, and 20% if both apply.

The bank portion funds at closing the way any commercial mortgage does. The CDC portion does not. That timing gap is the heart of how a 504 actually works.

What a debenture is, and why your money comes later

The CDC does not lend you its own cash. Instead, after your loan closes, the SBA guarantees a note called a debenture — a bond — equal to the CDC portion of your deal. Those debentures are gathered from CDCs all over the country, bundled into a monthly pool, and sold to investors in the capital markets. The proceeds from that sale are what actually fund the CDC half of your loan.

Because the debenture carries a 100% SBA guaranty, investors treat it as very safe, which is exactly why the rate can be low and fixed for decades. But it also means your funding depends on a scheduled sale that happens after you sign. In practice, the bank often advances the CDC portion as interim financing at closing, and the debenture sale “takes out” that bridge weeks later. You get your building either way; the mechanic is happening behind the scenes.

How your fixed rate is actually set

Here is the part that trips people up. On the bank portion, your rate is negotiated and known. On the CDC portion, your rate is locked on the day the debenture is sold — not the day you close. That rate is priced off U.S. Treasury yields for a comparable maturity, plus a market spread and the program’s ongoing fees baked in.

So when a loan officer quotes you an “estimated” 504 rate, treat it as exactly that. The real number is whatever the market produces at the next pooling. If Treasury yields drift up between your approval and the sale, your fixed rate moves with them; if they drift down, you benefit. You can follow the direction of those yields yourself — the U.S. Treasury publishes daily par yield curve rates — but you cannot pin your exact rate until the sale clears.

The upside is real: once that debenture sells, your CDC rate is fixed for the full life of the loan. There is no reset, no index adjustment, no payment shock years later. For a borrower who wants certainty on a 20- or 25-year obligation, that is the whole appeal.

The term options on the debenture

The CDC debenture comes in different maturities depending on what you are financing:

• 25-year and 20-year terms are generally used for real estate — buildings and land.
• 10-year terms are typically used for long-life machinery and equipment, which wears out faster than a building.

A longer term means a lower monthly payment but more total interest over the life of the loan. Because the CDC rate is fixed, the math is predictable from day one — which is more than you can say for a variable-rate conventional loan on the same property.

The fees stacked into the CDC portion

The debenture does not come free. The 504 program carries several fees, and most of them are financed into the loan rather than paid out of pocket, so you may never write a separate check for them — but you pay interest on them for the life of the loan. In broad terms, expect:

• A one-time processing or guaranty fee charged when the loan is made.
• An ongoing servicing fee paid to the CDC that services your loan.
• An ongoing fee to the SBA and to the central servicing agent that administers the debenture pools.
• Underwriter and funding fees tied to selling the debenture into the market.

The exact percentages are set by the SBA and can change by fiscal year, so do not anchor on a number a broker quotes from memory. Ask your CDC for the current fee schedule in writing, and ask specifically whether each fee is one-time or ongoing. The ongoing fees are part of your effective rate even though they are not labeled “interest.”

The prepayment question

Because the debenture is sold to investors who expect a certain return, paying off the CDC portion early is not as simple as mailing in a check. A 504 debenture carries a declining prepayment penalty in its early years, calculated off the debenture’s coupon rate and phasing out over roughly the first half of the term. If you think you might sell the property or refinance within a few years, price that penalty into the decision before you sign. It is one of the real trade-offs you accept in exchange for the low fixed rate.

What this means for you as the borrower

Put plainly: the 504 structure hands you a genuinely attractive deal — a long, fixed, low rate on a large chunk of your financing — in exchange for giving up control over the exact rate until the debenture sells, and in exchange for a prepayment penalty if you exit early. That is a fair trade for a business that intends to occupy and keep the property. It is a worse fit for a borrower who plans to flip or refinance quickly.

Three things to do before you commit:

• Ask when the next debenture sale is scheduled and what estimated rate the CDC is using, then watch Treasury yields in the gap so the final number is not a shock.
• Get the full fee schedule in writing and separate the one-time fees from the ongoing ones.
• Read the prepayment language and model what an early exit would actually cost.

The takeaway

The CDC half of a 504 loan is not funded by your lender — it is funded by a government-guaranteed bond sold into the market after you close, and your fixed rate is set by that sale. Understanding that one mechanic turns the “estimated rate” on your term sheet from a mystery into something you can anticipate and plan around. The low fixed rate is real and worth having. Just know how it gets made before you sign for it.

Important: MidBank is not a bank, a financial institution, or a financial advisor. We are an advocate and ISO affiliate that connects businesses to vetted third-party providers. This article is general information published on November 7, 2026, not legal, tax, or financial advice — rules and rates change, and your situation is specific to you. Confirm details with the primary sources linked above and with a qualified tax or legal professional before acting.