A HUD underwriter looks at a project's NOI from two angles: one NOI is used against HUD's debt service coverage ratio to determine the DSCR loan amount, and one is based on the appraiser's direct capitalization value (NOI divided by the market cap rate) — which determines the LTV loan amount. The two NOIs have different standards the underwriter must follow. The DSCR NOI is meant to mirror the property's reality while staying inside HUD's underwriting rules; the appraiser's Market NOI is what a hypothetical investor would expect the property to earn. The two usually are close, but they can differ on three lines — income, vacancy, and expenses — and having a lender know how to interpret the differences can produce materially more mortgage proceeds.
Everything that follows describes the 223(f), where the loan is sized on both value and coverage — so the appraiser's Market NOI and the DSCR NOI each drive a separate loan amount. The other common programs only put a DSCR NOI in play: the 221(d)(4) is sized to cost rather than to an appraised value, so the Market NOI doesn't drive its proceeds, and the 223(a)(7) streamlined refinance uses no new appraisal at all.
How HUD Builds the DSCR NOI
For the DSCR NOI, the underwriter starts from the property's current rent collection. Normally, the method is the latest rent roll's actual rent on occupied units plus the market rent on vacant units; that sum is the Gross Residential Rent Potential, and a vacancy factor comes off it. HUD's minimum vacancy depends on how much affordability the project carries — for a market-rate project it's 7%, including collection loss. Where the property's actual vacancy runs higher, the underwriter will normally use the actual rate. The underwritten vacancy is the greater of the minimum below and the property's own rate.
| Minimum Vacancy & Collection Loss | Property Type |
|---|---|
| 3% | Properties with HAP contracts covering 90% or more of units |
| 5% | LIHTC properties meeting the minimum set-aside requirements, or with attainable tax-credit rents at least 10% below market |
| 7% | Market-rate properties, or other affordable projects not meeting the 3% or 5% rules |
Pending change to watch. A draft HUD Mortgagee Letter circulated to lenders in spring 2026 included language that would let a market-rate property underwrite its DSCR vacancy at 5% — below the current 7% floor — where occupancy has held at that level for three years. The final language is not set and the change is not yet in effect. We're tracking it because, on a market-rate deal, moving the floor from 7% to 5% feeds straight into the DSCR NOI and the loan amount. (Noted June 2026; we'll update when HUD finalizes.)
HUD letting the latest month's rent roll set income is different from many programs, including Fannie Mae and Freddie Mac, which require that the underwritten income not exceed the annualized trailing-three-month collections. On a project with rising rents, the trailing-3 pulls the underwritten Rent Potential down — a lower DSCR, and possibly lower proceeds.
One unit's lease resets from $1,000 to $1,100 at the start of the most recent month. Compare how each method annualizes that unit:
Extrapolated across a building stepping rents up lease by lease, the gap adds real Gross Rent Potential the trailing-3 would strip out.
The latest rent roll also gives a fairer read on where the project will be at closing and after. Most leases run twelve months, so a year out the income looks more like today's rent roll than the trailing-3. It also lets HUD better underwrite a project still in lease-up, where the trailing-3 understates the stabilized rent roll — HUD's stated basis is to underwrite to the revenue actually being collected. From there the DSCR NOI runs through HUD's DSCR coverage mortgage amount test; our 223(f) loan sizing guide walks the full set of sizing tests.
Where the Appraiser Can Go Higher
The appraiser builds the Market NOI a little differently. Income comes from comparable projects' rents compared against the property's actual, current rents. If the property runs very low vacancy with rents below market, the appraiser can set income above the figure used in the DSCR NOI analysis.
The appraiser can also use a vacancy below the DSCR table. Where the DSCR analysis is locked at 7% for a market-rate project, the appraiser might conclude the market's vacancy is 4% and underwrite to 4%. That vacancy difference alone can add millions in mortgage proceeds if the LTV is constraining the mortgage amount, because the Market NOI drives appraised value and the LTV ceiling moves with it.
Where the Expense Lines Differ
Expenses can vary between the two NOIs the same way. The DSCR side wants expenses that reflect the property's reality; the appraiser wants expenses that reflect the marketplace, and the two get reconciled where they differ. Easy examples are an above-market management fee paid to a related entity, or a property insurance premium that runs unusually low.
The most common difference is the annual deposit to replacement reserves. The appraiser often carries $250 per unit; while the DSCR NOI must use the figure the Property Capital Needs Assessment (PCNA) sets during underwriting. Larger gaps in the total expenses can come from the cost of operating under affordability restrictions and from real estate taxes under abatements, TIFs, and similar arrangements.
What a Small Gap Is Worth
The two NOIs can finish close and still produce very different loan amounts. Say the appraiser concludes the market's management fee is $10,000 below the property's actual. At a 5% cap rate, that's roughly $160,000 of additional value — and additional LTV-constrained proceeds — off a single expense line.
None of that is gaming the rules. It's building each NOI to the standard HUD assigns it: reality on the DSCR side, the market on the appraisal side. On the right deal, that reconciliation is the difference between an adequate loan and the largest one the property can defensibly support.
Frequently Asked Questions
Working a Deal Where Proceeds Are Tight?
If you're sizing an acquisition or refinance and the loan amount is coming in below what the deal needs, the space between the DSCR NOI and the Market NOI is often where the room is. We underwrite both sides the way HUD and the appraiser actually build them, and we'll give you an honest read on where a deal's proceeds can move and where they can't. Send us the rent roll and trailing financials and we'll size it.