Most new investors assume the lender adds the full rent to their income. It does not. Fannie Mae has a specific formula, and a rule about landlord experience that catches almost every first-time buyer of a rental. Here is how it works, so the numbers you run match the numbers the underwriter runs.
On a purchase, Fannie Mae has the lender multiply the monthly gross rent by 75 percent, then subtract the property's full payment - principal, interest, taxes, insurance and any association dues. The result is called adjusted net rental income.
Rent $2,000 a month. 75 percent is $1,500.
Payment $1,700. $1,500 minus $1,700 is negative $200, which gets added to your monthly debts.
Payment $1,300. $1,500 minus $1,300 is positive $200 - but whether you can use it depends on step two.
The rent figure comes from the appraiser's rent schedule, or from a lease being transferred to you, supported by that schedule. If the lease is higher than market, the lender may use the lower number.
Fannie Mae lets the lender use positive rental income as qualifying income only if you have at least 12 months of property management experience. That is usually proven with a tax return showing rental income on Schedule E, or a lease signed at least 12 months before the application.
Positive adjusted net rental income adds to your income. The rental can help you qualify.
Positive rent can only offset the property's own payment. It can cancel the house out, but it cannot add to your income.
Negative rent counts against you either way. So on a first rental, your own income has to carry everything except the property's payment.
For a lease on a property not yet on your tax return, it cannot be with a family member or anyone with an interest in the deal, and the lender wants proof the lease is real: two consecutive months of rent deposits, or for a brand new lease, the security deposit and first month's rent with proof of deposit. A new lease must run at least six months.
One more limit worth knowing: rent from your own home - a one-unit primary residence, or the unit you live in - generally cannot be used to qualify. Buying a two- to four-unit and renting the other units is different, covered on house hacking a 2-4 unit. How many financed rentals you can hold is on how many rentals you can finance.
From the source: Fannie Mae Selling Guide B3-3.8-01, General Rental Income Information, and B3-3.8-02, Rental Income from the Subject Property (both 09/02/2026). Lender overlays can be stricter. Not a commitment to lend.
Renting builds someone else's wealth. Owning a rental builds yours. Get the full book free and start your move today.
Jason is also a mortgage broker. Questions?(843) 569-7283 / 843.LOW.RATE