Investment Property Mortgage Navigator

Choose the lane first

A conventional agency investment mortgage underwritten using borrower income is different from a private-investor DSCR or other business-purpose product.

Rental income

Agency rental-income treatment depends on the property, transaction, documentation and borrower history. Private-investor DSCR calculations use their own matrices.

Portfolio complexity

Multiple financed properties, reserves, ownership, short-term rentals and recently acquired rentals can change the analysis.

Rule vs overlay

Always separate an agency/investor rule from a lender overlay or a product the lender simply does not offer.

Choose the underwriting lane first

An agency investment mortgage, DSCR loan and portfolio loan may all finance a rental property, but they qualify the borrower/property differently. Start with occupancy, rent history, tax returns, entity/title, reserves and investment strategy.

Documents I would gather before calculating rental income

Current mortgage statements/PITIA for every retained property; Schedule E and applicable tax returns; leases; purchase closing statements and acquisition dates; appraisals or rent schedules when applicable; proof of current housing payments; insurance/HOA information; entity documents if an LLC is involved; and evidence of reserves. The correct calculation depends on what the property is and when/how it was acquired.

Common investor-loan mistakes

Calling 75% of rent 'income' without subtracting PITIA; using a lease when current agency policy requires another rent source; adding positive rental income when it is only allowed to offset housing expense; confusing cap rate with DSCR; applying a private investor's seasoning rule to Fannie/Freddie; and assuming an LLC-owned mortgage is counted the same as a personally obligated mortgage.

Investment Property Expert Library

Worked 2026 example: the rental that was purchased 20 days ago

A borrower applies for a new mortgage and also bought a non-subject rental 20 days before the new application. Under Fannie's September 2026 category for investment properties purchased within 45 days, the lender cannot use the lease to determine rent. If documented gross market rent is $3,000 and PITIA is $2,000, 75% of market rent is $2,250 and ANRI is +$250. But that $250 may only offset PITIA in this category—it is not added as $250 of positive qualifying income. If PITIA were $2,500, the $250 loss would enter DTI. This is the kind of distinction generic 'use 75% of rent' advice misses.

Primary sources to verify

• Fannie Mae — General Rental Income
• Fannie Mae — Investment Property Purchased Within 45 Days
• Fannie Mae — Multiple Financed Properties
• Freddie Mac — Investment Property Mortgages

Last reviewed September 15, 2026.