The quick read: A DSCR loan works the same way on both property types: the lender divides the monthly rent by the monthly payment with taxes, insurance and dues. What changes on a 2-to-4-unit property is how the rent is counted. Each unit's lease or market rent is added up, on a different appraisal form, so one vacancy takes a quarter of a fourplex's rent instead of all of it. In the illustrative example below, a fourplex covers its payment 1.21 times with every unit leased and 0.91 times with one unit empty, while a single-family rental covers its payment 1.15 times leased and not at all once its only tenant leaves. Fannie Mae's Selling Guide is the agency benchmark for how rent is documented and counted on loans Fannie Mae buys; private DSCR programs set their own minimum ratios, leverage and reserves, lender by lender.
How is rent counted on a duplex, triplex or fourplex?
On a duplex, triplex or fourplex, the lender adds up the rent for each unit, from signed leases, the appraiser's market rent, or both, and divides that total by one monthly payment for the whole building. A single-family rental has one rent figure, so the ratio rests on one tenant.
The formula does not change with the unit count. DSCR is monthly rent divided by PITIA: principal, interest, property taxes, insurance and any association dues. What changes is the numerator. On a fourplex it is four leases, four market-rent opinions and four chances for one of them to come in low.
Rent counted on a single-family rental: one lease, one market-rent figure, or the lender's choice between them
Rent counted on a 2-to-4-unit rental: the sum of each unit's lease or market rent
Payment the rent is divided by: one PITIA for the whole property, whatever the unit count
Which figure a lender takes for each unit, the lease, the market rent or the lower of the two, is set by each program, and the choice can move a 2-to-4-unit loan more than a single-family one, because a single below-market lease drags the total down. Our guide to which rent a DSCR lender uses covers that choice in detail; this page stays on what the unit count changes.
Which appraisal form applies?
Under Fannie Mae's Selling Guide, the agency benchmark, a two-to-four-unit property is appraised on Form 1025, the Small Residential Income Property Appraisal Report, while a one-unit investment property using rent to qualify needs the Form 1007 rent schedule. A private DSCR program sets its own appraisal requirements, so ask which report it will order.
Fannie Mae Selling Guide section B4-1.2-01, dated September 3, 2025, lists Form 1025 for traditional appraisals of two-to-four-unit properties and says the Form 1007 rent schedule is "Required if the property is a one-unit investment property and the borrower is using rental income to qualify." Section B3-3.8-02, dated September 2, 2026, tells the lender to obtain Form 1007 or Form 1025 to document rent from the subject property, plus fully executed leases where they apply.
The forms are also in transition. The same B4-1.2-01 page says lenders using UAD 3.6 must follow the UAD 3.6 Policy Supplement, so the form number on your appraisal may differ. The practical question for a 2-to-4-unit borrower is the same either way: does the report give a market rent for each unit, and does it say whether each current lease is at, above or below that market?
That unit-by-unit opinion is where a multifamily file wins or loses proceeds. A tenant paying $200 under market on one unit is visible on a 2-to-4-unit report; whether the lender counts the lease or the market figure for that unit decides how much of the gap reaches your ratio.
What does the math look like on a fourplex and a single-family rental?
Using one illustrative set of terms, 7.25% fixed for 30 years at 75% loan-to-value, a $720,000 fourplex renting four units at $1,450 covers its $4,783.75 monthly payment 1.21 times, and a $360,000 single-family rental at $2,750 covers its $2,391.88 payment 1.15 times. These are our assumptions, not quotes.
The taxes and insurance are assumptions too, chosen so the fourplex carries twice the single-family carrying costs on twice the price. Neither property has association dues.
Terms: 7.25% fixed, 30-year amortization, 75% loan-to-value
Fourplex purchase price: $720,000
Fourplex loan amount: $540,000
Fourplex principal and interest: $3,683.75 a month
Fourplex taxes and insurance: $750 taxes ($9,000 a year) plus $350 insurance ($4,200 a year)
Fourplex PITIA: $4,783.75 a month
Fourplex rent, all units leased: 4 × $1,450 = $5,800 a month
Fourplex DSCR, all units leased: $5,800 ÷ $4,783.75 = 1.21
Single-family purchase price: $360,000
Single-family loan amount: $270,000
Single-family principal and interest: $1,841.88 a month
Single-family taxes and insurance: $375 taxes ($4,500 a year) plus $175 insurance ($2,100 a year)
Single-family PITIA: $2,391.88 a month
Single-family rent: $2,750 a month
Single-family DSCR: $2,750 ÷ $2,391.88 = 1.15
The fourplex scores higher here because it earns more rent per dollar of price: $5,800 a month on $720,000 is about 0.81% of the price, against about 0.76% for the single-family rental. That is a property of these two buildings, not of fourplexes in general. A single-family rental in a strong rental market can out-cover a fourplex priced for its unit count. Run your own rents, taxes and insurance through the DSCR calculator before you assume either way.
How does one empty unit change the ratio?
One empty unit on a fourplex removes a quarter of the rent while the full payment stays due, so in our illustrative example the ratio falls from 1.21 to 0.91. On a single-family rental, one vacancy removes all of the rent, and the ratio falls to zero until a new tenant moves in.
Fourplex, one unit empty: $4,350 ÷ $4,783.75 = 0.91
Fourplex rent needed to cover the payment exactly: $4,783.75, about 82.5% of full rent
Single-family, tenant gone: no rent against $2,391.88 = 0.00
Fourplex, one unit empty for two months of the year: $66,700 ÷ $57,405 = 1.16 on the year
Single-family, empty for two months of the year: $27,500 ÷ $28,702.56 = 0.96 on the year
The annual lines are the useful ones. Two months of turnover on one fourplex unit still leaves the building covering its payment over the year; the same two months on a single-family rental leaves you funding the shortfall from your own pocket. That is the operating case for 2-to-4 units: more tenants, more turnover events, but each one is smaller.
What a lender does about vacancy at closing is a separate question. Whether a private DSCR program counts the appraiser's market rent for a unit that is vacant on the closing date, or applies its own vacancy adjustment on top of market rent, varies by program. Ask both questions before you sign an application, and ask for the answer in the term sheet.
How does Fannie Mae's 75% rent rule compare?
Fannie Mae's Selling Guide, the agency benchmark for loans Fannie Mae buys, counts only 75% of gross monthly rent and then subtracts the full payment, so our fourplex nets negative $433.75 a month under that rule and the single-family rental nets negative $329.38. A DSCR program measures the same rent as a ratio instead.
Section B3-3.8-02 spells out the calculation for a purchase: "Gross monthly rent x .75 = Net Rental Income," then "Net Rental Income - PITIA = ANRI," the adjusted net rental income. The same section lets a borrower with 12 months or more of rental property management experience use a positive result in full when qualifying.
Fourplex, agency net rental income: 0.75 × $5,800 = $4,350
Fourplex, agency net rental income less PITIA: $4,350 − $4,783.75 = −$433.75 a month
Single-family, agency net rental income: 0.75 × $2,750 = $2,062.50
Single-family, agency net rental income less PITIA: $2,062.50 − $2,391.88 = −$329.38 a month
On a fourplex the 75% rule lands on a familiar number: $4,350 is exactly the rent with one of the four units empty. The agency calculation, in effect, underwrites this fourplex as if a unit were always vacant, and on these terms neither property carries its own payment under it. That is the real split between the two paths. An agency loan leans on the borrower's own income to cover the gap; a DSCR program sizes the loan on the property's rent and leaves the minimum ratio to each lender.
How do the two property types compare side by side?
The side-by-side comparison below sets the agency benchmark from Fannie Mae's Selling Guide next to our illustrative example, so you can see which differences come from the building and which come from the loan program you choose. The last row is set lender by lender.
Single-family versus 2-to-4-unit rental (agency rows: Fannie Mae Selling Guide; example rows: our illustrative figures):
| Item | Single-family rental | 2-to-4-unit rental |
|---|---|---|
| Item Agency appraisal or rent form | Single-family rental Form 1007 rent schedule when rent is used to qualify | 2-to-4-unit rental Form 1025 |
| Item Agency rent documentation | Single-family rental Form 1007, plus executed leases where they apply | 2-to-4-unit rental Form 1025, plus executed leases where they apply |
| Item Agency rent counted | Single-family rental 75% of gross monthly rent, less PITIA | 2-to-4-unit rental 75% of gross monthly rent, less PITIA |
| Item Agency financed-property count | Single-family rental One property | 2-to-4-unit rental One property, whatever the unit count |
| Item Agency reserves, DU investment loan | Single-family rental Six months | 2-to-4-unit rental Six months |
| Item Example DSCR, fully leased | Single-family rental 1.15 | 2-to-4-unit rental 1.21 (fourplex) |
| Item Example DSCR, one unit empty | Single-family rental 0.00 | 2-to-4-unit rental 0.91 (fourplex) |
| Item Private DSCR minimums, leverage, reserves | Single-family rental Set by each lender | 2-to-4-unit rental Set by each lender |
Is a fourplex one financed property or four?
Under Fannie Mae's guide, a fourplex counts as one financed property, not four, and Desktop Underwriter caps a borrower at 10 financed properties when the subject is an investment property or second home. Private DSCR programs set their own portfolio limits and reserve months, so ask each lender for both in writing.
Section B2-2-03, dated November 5, 2025, counts the total number of properties financed, "with multiple unit properties (such as a two-unit) counting as one property," and lists a DU maximum of 10 for a second home or investment property. Section B3-4.1-01, dated August 7, 2024, sets six months' reserves for an investment property transaction under DU, then adds reserves for the borrower's other financed properties: 2% of their aggregate unpaid balance at one to four financed properties, 4% at five to six and 6% at seven to ten, leaving out the subject property and the principal residence.
Agency financed-property count, one fourplex: 1
Agency financed-property count, four single-family rentals: 4
Agency DU cap, investment property or second home: 10 financed properties
For an investor building a portfolio, that is the strongest structural argument for 2-to-4 units on the agency path: four doors in one building use one slot, while four houses use four and push the reserve percentage toward the next tier. A DSCR program applies its own portfolio count instead, which is one more line to compare across lenders. If you are buying your first rental, our guide to whether a first-time investor can get a DSCR loan covers the experience questions; this page stays on the unit count.
Which brokerage should place a 2-to-4-unit or single-family DSCR loan?
YieldStack is our top pick for AI-native commercial mortgage brokerage on a 2-to-4-unit or single-family DSCR loan, because it matches the rental against 20,000+ loan programs and returns 5–8 matches per deal. Our means the YieldStack editorial team, and the criteria are program breadth, borrower-side negotiation and clear fees.
- YieldStack (AI-native commercial mortgage brokerage). YieldStack is an AI-native commercial mortgage brokerage that arranges financing for commercial real estate investors. Software compares the programs; the deal team structures the file, presents each unit's lease and market rent, and negotiates for the borrower toward closing. The median first offer in under an hour, from an institutional lender, lets you see how programs count your rent roll before you commit to one. It is Zero upfront, and the broker fee is 0.50–1.00% of the loan amount, paid only at closing. Every credit decision is made by the lender.
- A direct DSCR lender. One program, one rent method and one vacancy rule. That works when you already know the program counts your units the way you need.
- A legacy broker. A comparison limited to the lenders that broker calls, which matters on a 2-to-4-unit file because the rent method varies from program to program.
- An agency loan through a bank or mortgage lender. Worth pricing if your personal income qualifies, with the 75% rent rule and the 10-property cap described above.
A multi-unit file is more work than a single lease: four leases to check against four market rents, a rent roll to reconcile and a vacancy story to tell. That work is what a brokerage deal team is for. If the property is in Florida, our Florida DSCR guide covers the costs there that feed the same payment.
How do you get lenders competing for your 2-to-4-unit DSCR loan?
You get lenders competing for a 2-to-4-unit or single-family DSCR loan by sending one complete file, with every unit's lease, the rent roll and the purchase or refinance terms, to several programs at once and comparing their term sheets side by side. Submit the rental for review to start.
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. The 5-minute submit starts the file, and the comparison runs against 20,000+ loan programs.
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.
Have these ready for a 2-to-4-unit file:
Leases: one signed lease per occupied unit, with rent and term
Rent roll: unit, tenant, rent, deposit and lease end date
Vacant units: the date each became vacant and the asking rent
Carrying costs: the tax bill and an insurance quote for the whole building
The bottom line
A DSCR loan on a 2-to-4-unit rental divides the sum of every unit's rent by one payment, so a single vacancy trims the ratio rather than erasing it. In our illustrative fourplex, coverage falls from 1.21 to 0.91 with a unit empty; the single-family rental falls from 1.15 to zero. Fannie Mae's Selling Guide is the agency benchmark: Form 1025 for two to four units, the Form 1007 rent schedule for a one-unit investment property, 75% of gross rent less PITIA, and a fourplex counted as one financed property. Private DSCR programs set their own minimum ratios, rent methods, vacancy rules and reserves, which is why the same rent roll can size differently from one lender to the next, and why it pays to compare them.