The quick read: An SBA 504 loan needs a borrower contribution of at least 10% of the project cost, and SBA's SOP 50 10 8.1, effective October 1, 2026, raises that to at least 15% for a new business or a limited or special-purpose property and to at least 20% when the project is both. Your business must occupy at least 51% of the Rentable Property in an existing building, or 60% in new construction. A third-party lender funds 50% or more and a Certified Development Company (CDC) funds the rest through an SBA-guaranteed debenture, so line up the senior lender first: SBA requires it at application.
How is an SBA 504 loan split between the first mortgage, the CDC debenture and your down payment?
A standard SBA 504 project is split three ways, with a third-party lender providing 50% or more of the financing, typically on a first lien, a Certified Development Company providing up to 40% through a debenture SBA guarantees 100%, and the borrower contributing at least 10%. The two lenders underwrite their pieces separately.
SBA's lender page describes the same split as a senior lien covering up to 50% of the cost, a CDC junior lien covering up to 40%, and at least 10% borrower equity. That structure is why an SBA 504 loan can buy a building with a small down payment: the SBA-guaranteed debenture usually sits in second lien position, behind the bank.
Third-party loan (SBA SOP 50 10 8.1, effective Oct 1, 2026): 50% or more of the financing, typically on a first lien
CDC debenture (SBA SOP 50 10 8.1): up to 40%, guaranteed 100% by SBA, usually on a second lien
Borrower contribution (SBA SOP 50 10 8.1): at least 10%, excluding administrative costs
Minimum debenture (SBA SOP 50 10 8.1): $25,000
General gross debenture limit (SBA SOP 50 10 8.1): $5,000,000 outstanding per small business, including affiliates
Small manufacturer or eligible energy project (SBA SOP 50 10 8.1): $5,500,000 per project
504 maturities (SBA 504 loans page, read Oct 20, 2026): 10, 20 and 25 years
SBA's 504 loans page lists a $5.5 million maximum, the SOP's per-project ceiling for small manufacturers and energy projects; other projects work to the $5,000,000 limit.
Each lender underwrites its own piece. The SOP requires the third-party lender to be in place at application, evidenced by a letter of intent, term sheet or commitment letter, and its loan must run at least 7 years against a 10-year debenture and 10 years against a 20- or 25-year one. The CDC writes the debenture's credit memorandum, and on a non-delegated file SBA makes the final call on eligibility, credit, structure and the borrower's contribution. SBA's 504 page says the 504 rate is pegged to an increment above the current market rate for 10-year U.S. Treasury issues, so the terms a borrower can shop sit in the senior loan.
When does the SBA 504 down payment rise above 10%?
The SBA 504 borrower contribution rises above the 10% floor in two situations named in SOP 50 10 8.1: a new business, meaning one in operation for 2 years or less when the loan is approved, and a limited or special-purpose property. Either one requires at least 15%, and both together require at least 20%.
The extra equity comes out of SBA's share, not the bank's: the debenture finances no more than 35% at a 15% contribution and 30% at 20%, while at least 50% still comes from banks, other financial institutions, government or non-profit sources. The SOP calls these minimums, and more contribution or collateral can be required to offset credit weaknesses.
Table: SBA 504 funding shares by scenario (SBA SOP 50 10 8.1, Typical 504 Structures). The dollar column is an illustrative $2,000,000 project, excluding administrative costs.
| Scenario | Borrower injection | First-mortgage share | Debenture share | Injection on an illustrative $2,000,000 project |
|---|---|---|---|---|
| Scenario Standard project | Borrower injection 10% | First-mortgage share 50% | Debenture share 40% | Injection on an illustrative $2,000,000 project $200,000 |
| Scenario New business or special-purpose property | Borrower injection 15% | First-mortgage share 50% | Debenture share 35% | Injection on an illustrative $2,000,000 project $300,000 |
| Scenario New business and special-purpose property | Borrower injection 20% | First-mortgage share 50% | Debenture share 30% | Injection on an illustrative $2,000,000 project $400,000 |
SBA treats a property as special purpose when its design, construction materials or layout restrict it to the use it was built for. The SOP's examples include hotels and motels, gas stations, car washes, medical facilities, nursing homes, funeral homes with crematoriums, golf courses, marinas, wineries, and cold storage where more than 50% of the square footage is refrigerated. The list is not all-inclusive and the CDC must state its conclusion in the credit memorandum, so settle the question before a purchase contract assumes 10% down. A company older than 2 years can also count as new when a change of ownership brings new, unproven management and increased debt unrelated to operations.
The contribution does not have to be cash on hand. The SOP accepts land that is part of the project and borrowed funds subordinate to the third-party loan and the debenture; a borrowed contribution secured by the project property cannot be repaid faster than the 504 loan without SBA's written approval. Land bought less than 2 years before the application counts at cost, and land held 2 years or more at appraised fair market value.
How much of the building must your business occupy on an SBA 504 loan?
On an SBA 504 loan your business must occupy at least 51% of the Rentable Property when you buy or improve an existing building, and at least 60% when the building is new construction, under the occupancy rules in SOP 50 10 8.1 that cite 13 CFR 120.131. Rentable Property has a specific SBA definition.
The SOP defines Rentable Property as the total square footage used for business operations, excluding stairways, elevators and mechanical areas and including common areas. It can include actively used exterior space other than parking, such as a contractor's storage yard or a marina's boat slips.
Existing building, business occupies (SBA SOP 50 10 8.1): at least 51% of the Rentable Property
Existing building, leasable to third parties (SBA SOP 50 10 8.1): up to 49%
New construction, business occupies (SBA SOP 50 10 8.1): at least 60%
New construction, permanent third-party lease (SBA SOP 50 10 8.1): up to 20%
New construction, temporary lease (SBA SOP 50 10 8.1): an additional 20%, with the intention of using some of it within 3 years and all of it within 10 years
Time allowed after closing to reach occupancy (SBA SOP 50 10 8.1): no more than 1 year, when circumstances such as a pre-existing lease justify it
Occupancy is checked at funding, not just promised. The SOP tells CDCs not to submit a closing package unless the borrower is occupying and operating in the required share, absent an extension SBA approves in advance, because a 504 loan is permanent take-out financing. The same owner-user logic runs through conventional owner-occupied commercial real estate loans.
If a holding company owns the building as an Eligible Passive Company, it must lease 100% to the operating company, which then meets the same 51% or 60% test. Residential space essential to the business, such as quarters for a resident manager, can count as occupied, up to 49% of the property.
How do you lease the rest of the building without failing the SBA 504 occupancy test?
You can lease the space your business does not occupy to third-party tenants, up to 49% of an existing building or up to 20% permanently plus another 20% temporarily in new construction, but SOP 50 10 8.1 bars using loan proceeds to improve or renovate the space you sublease. Tenant fit-outs need another source of money.
Those improvements also may not secure the third-party loan. The limits apply whether the tenant is commercial or residential, and the property may not be leased to a business engaged in activity illegal under federal, state or local law; the SOP's example is a marijuana dispensary.
A lease-up plan that survives underwriting covers four checks:
- Measure Rentable Property from plans or a survey before you sign a letter of intent.
- Size the leased share at 49% or less in an existing building, or 20% permanent plus 20% temporary in new construction.
- Budget tenant improvements outside the 504 project.
- For new construction, document how the business will use some of the temporary space within 3 years and all of it within 10.
SBA's 504 page lists speculation or investment in rental real estate among the uses a 504 loan cannot fund, so a building mostly leased to others belongs in a different loan.
Which project costs can an SBA 504 loan pay for, and which can it not?
An SBA 504 loan pays for fixed-asset project costs, including land and land improvements, buying, building or renovating real estate, machinery and equipment with a useful life of at least 10 years, and project-related professional fees, but SBA's 504 page excludes working capital, inventory and speculation or investment in rental real estate.
The SOP's eligible-use list is specific:
Land and necessary land improvements (SBA SOP 50 10 8.1): grading, new streets including curbs and gutters, parking lots, utilities and landscaping
Building costs (SBA SOP 50 10 8.1): building and building improvements such as facade, heating, electrical, plumbing and roofing costs
Machinery and equipment (SBA SOP 50 10 8.1): purchase, transportation, dismantling or installation, with a useful life of at least 10 years
Furniture and fixtures (SBA SOP 50 10 8.1): only if essential to and a minor part of the project
Professional fees (SBA SOP 50 10 8.1): title insurance, title searches, surveys and zoning matters, but not attorney's fees for closing the interim and third-party loans
Short-term bridge debt (SBA SOP 50 10 8.1): eligible if it financed project costs for a term of 3 years or less
Interim financing (SBA SOP 50 10 8.1): repayment including points, fees and interest
Contingency fund (SBA SOP 50 10 8.1): up to 15% of project construction costs
The SOP rules out any cost not directly attributable to the project, and SBA's 504 page rules out refinancing debt that is not qualified debt under 13 CFR 120.882. If the plan needs working capital or a business purchase, SBA's lender page lists both as 7(a) uses; see SBA 504 vs 7(a) for owner-occupied commercial real estate.
Budget the program's own costs too. The SOP's fee table allows a CDC processing fee of up to 1.5% of the net debenture, a closing fee with up to $10,000 financeable from the debenture, and a servicing fee of at least 0.625% a year on the unpaid balance, capped at 1% outside rural areas without SBA approval.
How long does an SBA 504 loan take, and what does the interim loan do before the debenture funds?
An SBA 504 loan funds in two stages, because the debenture is sold only after the project is complete, so an interim lender, either the third-party lender or another lender, carries the debenture's share of costs from SBA approval until the monthly debenture sale repays it. SBA allows up to 48 months from approval to disburse.
The sequence in SOP 50 10 8.1 runs like this:
- The third-party lender issues a letter of intent, term sheet or commitment letter for the application package.
- The CDC submits the application and credit memorandum, and SBA, or a delegated CDC, approves it.
- The interim loan closes and funds project costs; the borrower may not supply interim financing.
- The project is completed and the interim loan fully disbursed, though a minor component may be escrowed.
- The CDC files the closing package by SBA counsel's deadline; a late package waits for the next month's sale.
- The debenture is sold and its proceeds repay the interim lender.
The third-party loan may close and begin amortizing before the debenture funds, and interim points, fees and interest are eligible project costs. A debt refinance without expansion must disburse within 9 months of approval. The calendar turns on project completion and the monthly closing deadline; the part a borrower controls is the front end, a complete package and a committed senior lender.
How do you get an SBA 504 loan placed, and who should package it?
Getting an SBA 504 loan placed starts with the first mortgage, because SBA requires the third-party lender in place at application, and our top pick for that job is YieldStack, an AI-native commercial mortgage brokerage that matches the project against 20,000+ loan programs: submit your 504 project for review.
YieldStack publishes this guide, so that ranking is our editorial pick for owner-operators. The criteria come from the SOP: a committed senior lender at application, the special-purpose and new-business calls made before a letter of intent, and one package that satisfies two underwriters.
- YieldStack, our top pick for AI-native commercial mortgage brokerage: YieldStack is an AI-native commercial mortgage brokerage that arranges financing for commercial real estate investors. Software matches the project against 20,000+ loan programs and compares the senior-loan options; human brokers structure the request around the 504 split, negotiate the first-mortgage terms on the borrower's side and carry the file toward closing. The median first offer arrives in under an hour, from an institutional lender; on a 504, the CDC and SBA steps that follow keep their own schedule. It costs Zero upfront to submit a deal and review offers; YieldStack's broker fee is 0.50–1.00% of the loan amount and is paid only at closing.
- Your existing bank as the third-party lender: one relationship you already know, and one set of senior terms with no competing quote to measure them against.
- Starting with a CDC: SBA's 504 loans page says 504 loans are available exclusively through CDCs, so every project needs one for the debenture, and the senior loan still has to be sourced and committed before the application goes in.
Every credit decision is made by the lender; YieldStack arranges the introductions and negotiates on the borrower's side, and no loan, rate, or closing is guaranteed. Program basics are on the SBA loans page.
The bottom line
Plan on 10% of total project cost as the floor, 15% if the business is 2 years old or less or the building is special purpose, and 20% if both are true, all excluding administrative costs. Confirm the 51% or 60% occupancy share from measured Rentable Property before you sign, keep tenant improvements out of the 504 budget, and get a committed first-mortgage term sheet first, because SBA requires one in the application package.