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Loan-type guide

Interest-Only DSCR Loan: The Investor's Deep Dive

Interest-only DSCR loan guide: 10yr IO + 20yr amortization structure, DSCR recalculation rules, rate premiums, recast risk, and when IO pays off.

Updated 17 min read
Interest-Only — DSCR loan product illustration

Interest-only is the single most misunderstood DSCR loan structure. Investors use it to meaningfully improve cash flow and qualify deals that would otherwise fail DSCR — but most don’t understand how the recast works, how different lenders calculate DSCR under IO, or when the structure actually pays off versus full amortization.

This guide is the complete deep-dive: how the IO structure actually works, the exact payment math with real numbers, how each major lender calculates DSCR (they don’t all treat it the same way), the rate premium and LTV haircuts, the strategic cases where IO wins, and the pitfalls that catch 60% of first-time IO borrowers at year 10.

What an Interest-Only DSCR Loan Actually Is

A DSCR interest-only loan has two distinct phases inside one 30-year term:

Phase 1 — Interest-Only Period (years 1–10 most commonly):

  • You pay ONLY the monthly interest on the loan balance.
  • No principal reduction — your loan balance stays exactly the same each month.
  • Payment is stable (if fixed rate) or variable (if ARM) during this period.

Phase 2 — Amortizing Period (years 11–30):

  • The remaining loan balance (your original principal if you made only IO payments) is re-amortized over the remaining years.
  • Payment jumps meaningfully — typically 25–40% higher — because you’re now paying 20 years of amortization on the same balance, at whatever rate was set at origination.
  • The total term stays 30 years, so the last payment happens in month 360.

The most common structure is 10yr IO + 20yr amortizing = 30yr total. A few lenders offer 5yr IO + 25yr amortizing = 30yr total. A smaller set offer 10yr IO + 30yr amortizing = 40yr total (rare).

The Payment Math (Concrete Example)

Loan amount: $300,000. Rate: 7.25%. Term: 30 years.

Fully-amortizing P&I: $300,000 × (0.0725/12) ÷ (1 − (1 + 0.0725/12)^−360) = $2,046.53 / month

Interest-only payment (years 1–10): $300,000 × 0.0725 ÷ 12 = $1,812.50 / month

Difference: $234 per month = 12.9% lower during the IO period.

Year-11 recast (if still held, balance still $300,000): Re-amortize $300K over remaining 20 years at the same 7.25% = $2,371.58 / month

So you pay $1,812.50 for 10 years, then jump to $2,371.58 — a 31% payment increase at recast. If you refinance or sell before year 10, you never see the recast.

How DSCR Calculation Changes Under IO

This is where lenders diverge and where borrowers get blindsided. There are two camps:

Camp 1 — DSCR Qualified on IO Payment (“Generous”)

The lender uses the actual IO monthly payment in the PITIA denominator. Example:

  • Rent: $2,200
  • IO P&I: $1,812.50
  • Taxes: $300
  • Insurance: $125
  • HOA: $0
  • PITIA (IO-based): $2,237.50
  • DSCR: 2,200 / 2,237.50 = 0.98

Lender accepts at 0.75 DSCR minimum → qualifies easily.

Lenders that qualify DSCR on IO: Griffin Funding, Easy Street Capital, HomeAbroad, OfferMarket, LendingOne (select products).

Camp 2 — DSCR Qualified on Fully-Amortized P&I (“Strict”)

The lender uses the P&I that would apply if the loan were fully amortizing from day one, even though you’re actually paying IO. Example (same deal):

  • Rent: $2,200
  • Fully-amortized P&I: $2,046.53
  • Taxes: $300
  • Insurance: $125
  • PITIA (amortized-based): $2,471.53
  • DSCR: 2,200 / 2,471.53 = 0.89

Lender accepts at 0.75 DSCR minimum → still qualifies, but the DSCR is meaningfully lower.

Lenders that qualify DSCR on fully-amortized P&I: CoreVest (most products), many institutional portfolio lenders, some Kiavi programs, A&D Mortgage on select files.

Why Investors Use IO: The Real Strategic Picture

Interest-only isn’t just about qualifying a weaker deal. Experienced investors use IO strategically:

1. Maximize Cash Flow on Appreciation Plays

In markets where appreciation is expected to outpace amortization, every dollar of principal paydown is “dead money” — your return comes from appreciation, not pay-down. IO keeps that capital available as cash flow you can redeploy into the next deal.

Example: $500K property expected to appreciate 5%/yr. Year 1 appreciation = $25K. Year 1 principal paydown on an amortizing loan = ~$3,500. The $3,500 you would have paid down is better deployed as down payment on another rental.

2. BRRRR Refi Stabilization

After a BRRRR refi, cash flow is often tight because the property just absorbed rehab and the rent is still ramping. IO during the 12–36 month stabilization window keeps DSCR healthy while you optimize rent, reduce vacancy, and consider next moves.

3. Short-Term Rental Seasonal Cash Flow

STRs have seasonal revenue volatility. The off-season can strain DSCR. IO lowers the baseline monthly payment, making the off-season less painful. Year-round, the blended DSCR looks healthier.

4. Portfolio Scaling

When you’re adding deals quickly, each new loan soaks up reserves. IO frees up monthly cash that accumulates into future down payments or reserves for the next acquisition. The compounding effect over a 5-year aggressive scaling phase can be the difference between 8 properties and 14.

5. Exit Timing

If you plan to sell or 1031 within 7 years, the amortization benefit of a standard loan is minimal — you’ll never own the loan outright anyway. IO simply preserves more monthly cash flow during the hold.

When NOT to Use Interest-Only

  • Long-term buy-and-hold where you want the loan paid off. If your plan is to retire on a paid-off portfolio, IO works against you.
  • Aggressive amortization strategy. Some investors deliberately pay down debt to reduce risk. IO conflicts with that philosophy.
  • Rising-rate environments with floating IO. An IO ARM means your payment can rise DURING the IO period as rates adjust. Stick with fixed-rate IO in rate-uncertain environments.
  • Properties with thin DSCR (under 0.85 even on IO). If the deal only pencils with IO and it’s a long-hold, you’re one rate environment away from trouble at recast.

Lenders Offering Interest-Only DSCR Loans

This list reflects the Q1 2026 market. Features vary; always verify at application.

Griffin Funding — 10yr IO + 20yr amort, DSCR qualified on IO payment, up to 80% LTV (with conditions), 680 FICO min, 5/1 and 7/1 ARM also available.

Easy Street Capital — 10yr IO, STR-friendly, DSCR on IO, up to 75% LTV on IO products, integrated with short-term rental revenue projections.

Visio Lending — 10yr IO, qualifies DSCR on the IO payment for most products, institutional-backed pricing, strong SFR focus.

HomeAbroad — 10yr IO available on foreign national and domestic products, DSCR on IO, 70–75% LTV on IO, ITIN and entity-friendly.

Kiavi — IO available on select rental loan products, DSCR treatment varies by product line (some IO, some P&I), strong for BRRRR refi.

OfferMarket — IO as a standard option, DSCR on IO, competitive pricing, streamlined underwriting.

CoreVest — IO on individual and portfolio products, typically qualifies DSCR on fully-amortized P&I (strict), institutional investor clientele.

Lima One Capital — 10yr IO available on DSCR 30 program, strong BRRRR-focused team.

A&D Mortgage — IO on select DSCR products, qualification varies by program.

LendingOne — 10yr IO standard, DSCR on IO for most files.

Verify specifics on our lender comparison page or get matched to see live offers.

Rate Premium for Interest-Only

IO is a lender-preferred risk variation, so it carries a pricing premium:

StructureRate Premium vs Base Amortizing
30yr fully amortizing0.000% (base)
10yr IO + 20yr amort+0.125% to +0.375%
5yr IO + 25yr amort+0.125% to +0.250%
10yr IO + 30yr amort (40yr term)+0.500% to +0.875%
IO ARM (5/6 or 7/6)varies with index, often +0.250% to +0.500% vs. fixed IO

On a $300K loan, a 0.25% rate premium = roughly $625/year in interest. If IO saves you $230/month ($2,760/yr) in cash flow, the rate premium is a good trade even after accounting for the lost amortization benefit.

LTV Haircut Sometimes Applies

Some lenders cap LTV lower on IO products:

  • Standard amortizing: up to 80% LTV
  • IO: capped at 75% LTV at the same lender

If you’re targeting max LTV, ask specifically whether IO has the same LTV grid. The haircut is about a 5% down payment increase — $15K on a $300K purchase.

The Recast at Year 10: What Actually Happens

At month 121, your loan enters the amortizing period. The mechanics:

  1. Your rate stays the same if you have a fixed-rate IO. (If ARM, the rate is whatever the index + margin dictates at that time.)
  2. Your remaining balance is the same as your original balance (since you made no principal payments).
  3. The remaining balance amortizes over 20 years (for a 10+20 structure).
  4. Your new payment is higher. For a $300K loan at 7.25%, the payment jumps from $1,812.50 (IO) to $2,371.58 (amortizing 20-year) — a 31% increase.

You have three options at recast:

  • Accept the new payment if cash flow supports it.
  • Refinance into a new loan (new appraisal, new closing costs, new PPP).
  • Sell or 1031 exchange before the recast if the math doesn’t work.

40-Year Interest-Only: The Niche Product

A handful of lenders offer a 40-year term with IO for the first 5 or 10 years. The structure:

  • 10yr IO + 30yr amortizing = 40yr total
  • Lower fully-amortized payment because the amortization runs over 30 years instead of 20
  • Rate premium of 0.5%+ over the standard 30-year IO
  • Often restricted to loans above $500K and borrowers with 740+ FICO

When it makes sense: long-hold investors who want maximum cash flow flexibility and are willing to pay a rate premium for it. The product is relatively rare — typically available through portfolio DSCR lenders and a few specialty shops.

Pitfalls to Avoid

”The Recast Won’t Happen to Me”

Most IO borrowers assume they’ll sell or refinance before year 10. Reality check: market conditions at year 10 may not support the refinance you planned. Build your pro forma as if the recast happens.

Using IO on a Thin-Margin Deal

If your deal barely pencils on IO at 0.85 DSCR, what happens at recast when the payment jumps 30%? DSCR drops to ~0.65 at the same rent. You’re now in trouble — either rent has grown meaningfully, or you’re refinancing under duress.

Ignoring the Lost Amortization

Over a 10-year IO period on a $300K loan at 7.25%, amortization would have paid down roughly $43K in principal. That’s $43K of forgone equity build. If the property appreciates, this is fine — your equity grew from appreciation. If the property stays flat, you have $43K less equity than you would on an amortizing loan.

Confusing IO with ARM

IO is about payment structure (interest-only vs. P&I). ARM is about rate structure (fixed vs. adjustable). You can have:

  • Fixed-rate IO (rate fixed, IO for 10 years)
  • ARM IO (rate adjusts AND payment is IO)
  • Fixed-rate amortizing (standard)
  • ARM amortizing (rate adjusts, P&I from day one)

Understand which combination your loan is. ARM IO is the riskiest — rate can rise during the IO period, spiking your payment even before the recast.

Qualifying on IO But Underwriting on P&I Reserve Requirement

Some lenders calculate DSCR on IO but calculate reserve requirements (6 months of PITIA) on the fully-amortized payment. So you qualify at the IO payment but need reserves against the higher P&I number. Ask.

Forgetting Prepayment Penalty Applies

Refinancing at year 10 to escape the recast still triggers any remaining prepayment penalty. Most PPPs expire by year 5, but verify.

The Bottom-Line Decision Framework

Choose IO when:

  • Your hold period is 3–8 years
  • The property has appreciation upside
  • You are deploying the cash-flow savings into additional investments
  • Your DSCR is borderline and IO qualification is decisive
  • You can comfortably handle the recast payment (or have a refi plan)

Choose full amortization when:

  • You’re in long-term buy-and-hold mode (15+ years)
  • You want the loan paid off at year 30
  • Your DSCR is comfortable on P&I (1.15+)
  • Rate environment is uncertain and you want principal reduction as a hedge
  • You have no specific use for the monthly cash flow savings

Model both structures in our DSCR calculator and compare the total cost of ownership in the refinance timing tool.

Bottom Line

Interest-only DSCR loans are a precision instrument. They improve qualification, preserve cash flow, and support faster portfolio scaling — but they come with a real cost in forgone amortization and the recast risk at year 10. The investors who win with IO are the ones who understand exactly how their lender calculates DSCR, model the recast rather than assume a refinance, and match the structure to a specific strategy.

Ready to price an IO DSCR loan on your specific file? Get matched with 3–5 IO-friendly lenders and compare live offers.

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Frequently asked questions

An interest-only DSCR loan has an initial period (usually 10 years) where you only pay interest, followed by an amortizing period (usually 20 years) where you pay principal + interest on the remaining balance, all within a 30-year total term.
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