80/10/10 Piggyback Loan or Monthly PMI? The Real 5-Year Cost on a $400,000 Home With 10% Down
On a $400,000 home with 10% down, splitting the financing into an 80/10/10 piggyback loan comes out about $29,000 ahead of taking one 90%-loan-to-value mortgage and paying monthly private mortgage insurance (PMI) over the first five years, in the worked example below. The gap keeps growing every year PMI stays on the single loan — which, by amortization alone, is more than eight and a half years.
Key takeaways
- On a $400,000 home with 10% down, an 80/10/10 piggyback loan's combined payment is about $2,659/month versus about $2,916/month for one 90% loan with monthly PMI, in this worked example.
- Over 5 years, the piggyback path costs roughly $29,080 less once both the cash paid and the remaining loan balances are counted together.
- The PMI route doesn't just cost more up front — the mortgage insurance itself persists for more than 8.5 years by amortization alone, with no home-price appreciation assumed.
- The result flips if the borrower's actual PMI quote comes in well below the rate used here; PMI pricing varies by insurer, coverage level and lender arrangement, so this is a framework to run with your own quote, not a universal rule.
Figures checked: November 11, 2026.
The two paths, same $400,000 home
Assume a $400,000 purchase, a 10% down payment of $40,000, a 760+ credit score, and the current Freddie Mac Primary Mortgage Market Survey average of 7.18% for a 30-year fixed first mortgage (week of November 5, 2026).
Path A — 80/10/10 piggyback: a $320,000 first mortgage (80% of value) at 7.18% for 30 years, plus a $40,000 second mortgage (10% of value) structured as a fixed-rate home equity loan on a 10-year term at 8.268% — the average 10-year home-equity-loan rate reported by the Mortgage Research Center as of November 4, 2026. A variable-rate HELOC at a similar starting rate is the other common way to structure the second loan; see the HELOC-versus-fixed-home-equity-loan comparison for how that trade-off plays out on its own.
Path B — single 90% LTV loan with PMI: one $360,000 first mortgage at the same 7.18%, plus monthly private mortgage insurance. The PMI rate used here, 1.59% of the loan amount per year, comes from a published Genworth borrower-paid rate card for a 90% LTV loan with 25% coverage and a 760+ credit score — the coverage level lenders commonly select on a 90% LTV conventional loan. Actual PMI quotes vary by insurer and lender; this is one real, cited rate card, not every possible quote.
The year-by-year cost comparison
The table tracks, at each point in time, the cash already paid (principal, interest and PMI) plus the loan balance still owed — the combination is the fairest way to compare two structures that pay down debt at different speeds.
| Point in time | Path A (piggyback) — cash paid + remaining debt | Path B (PMI) — cash paid + remaining debt | B minus A |
|---|---|---|---|
| Year 1 | $31,905 + $354,176 = $386,081 | $34,989 + $356,468 = $391,457 | $5,376 |
| Year 3 | $95,716 + $341,099 = $436,815 | $104,968 + $348,599 = $453,566 | $16,751 |
| Year 5 | $159,527 + $325,856 = $485,383 | $174,946 + $339,518 = $514,463 | $29,080 |
| Year 8.6 (PMI's earliest removal point) | $273,855 + $291,950 = $565,805 | $300,324 + $319,611 = $619,935 | $54,130 |
Methodology and assumptions: standard fixed-rate amortization for all three loans (the $320,000 and $360,000 first mortgages at 7.18%/30 years; the $40,000 second mortgage at 8.268%/10 years); PMI charged monthly on the full $360,000 original balance at 1.59%/year until the balance reaches 80% of the original $400,000 price ($320,000) through scheduled amortization alone, with no home-price appreciation assumed. Property taxes, homeowners insurance and HOA dues are identical in both paths and are left out because they don't affect the comparison.
Why the piggyback loan wins here
The mechanism is straightforward once it's laid out: the second mortgage in Path A carries a higher interest rate (8.268% vs. the implied cost of PMI), but every dollar of its payment buys down principal — it is debt the borrower owns equity against from day one, on a 10-year payoff schedule. PMI in Path B is a pure expense with no equity attached; it does not reduce the loan balance by a single dollar, and at 1.59% of $360,000 a year, it adds up to more than the extra interest cost of the smaller, faster-amortizing second loan. The gap compounds every month PMI remains in place, which is why it roughly triples between Year 1 and Year 5 in the table above.
If starting from scratch today with this specific rate card, the piggyback structure is the better-documented math — but that conclusion rests entirely on the 1.59% PMI rate used here, not on piggyback loans being inherently superior.
Where this flips: when PMI could still be the better deal
Three realities cut the other way and are worth checking before assuming the table above applies to any specific loan. First, PMI pricing is not fixed: published borrower-paid rate cards range roughly from well under 1% to well over 2% a year depending on the insurer, the exact LTV band, the coverage percentage the lender selects, and the borrower's credit tier — a buyer who qualifies for a materially lower PMI rate than 1.59% could see Path B pull ahead instead. Second, PMI's cost falls automatically as the loan amortizes and, more importantly, as home values rise; this comparison deliberately assumes zero appreciation, and any price gain shortens PMI's life in Path B without touching the fixed second-mortgage payment in Path A. Third, a second mortgage is a second lien with its own closing costs, its own qualification hurdle on top of the first loan, and — if it's a HELOC rather than a fixed loan — a rate that can rise with short-term interest rates, a risk a fixed-rate PMI percentage doesn't carry. A buyer should run this same year-by-year comparison with their own actual PMI quote and second-mortgage quote rather than treating the rates used here as universal.
Qualification and paperwork differ, too. A single 90% LTV loan with PMI is underwritten once, against one set of income and asset documentation. A piggyback structure is effectively two loans closed at the same time — often, but not always, with the same lender — which can mean a second set of closing costs (origination fee, title work on the second lien, a possible appraisal fee) and a second debt-to-income calculation the borrower has to clear. Those closing costs are not included in the year-by-year table above, and on a smaller second loan they can meaningfully narrow the piggyback's advantage in the first year or two, even though they don't change the ongoing monthly math. On the tax side, mortgage interest on both the first and second loan in a piggyback structure is generally deductible under the same acquisition-debt rules as a single loan, for borrowers who itemize; PMI's federal deductibility has changed from one tax year to the next and should be checked against current IRS guidance rather than assumed.
FAQ
Is an 80/10/10 piggyback loan cheaper than paying PMI?
In this worked example — a $400,000 home, 10% down, 7.18% first-mortgage rate, an 8.268% 10-year second mortgage and a 1.59% PMI rate — the piggyback structure is cheaper by about $29,080 over 5 years. The result depends on the actual PMI and second-mortgage rates quoted to a specific borrower.
How long does PMI last on a 90% LTV loan?
In this example, with no home-price appreciation, the loan balance reaches 80% of the original purchase price — the point a borrower can request PMI cancellation under the Homeowners Protection Act — after about 103 months, or roughly 8.6 years, through scheduled amortization alone. A lender must automatically cancel PMI once the balance reaches 78% of the original value even without a borrower request. Home-price appreciation can shorten this considerably.
What's a typical PMI rate for a 10% down payment?
Published borrower-paid rate cards vary by insurer, coverage level and credit score; the example in this article uses 1.59% annually (a Genworth rate card figure for 90% LTV, 25% coverage, 760+ credit score). Rates for the same LTV band can run both lower and higher depending on the specific insurer and loan program.
Does the second mortgage in a piggyback loan have to be a HELOC?
No — it can be structured as either a variable-rate HELOC or a fixed-rate closed-end second mortgage (a home equity loan), as modeled in this article. Each has different rate-risk and payment characteristics.
Can I pay off the piggyback second mortgage early with a refinance?
Yes, and many buyers do once the combined first-and-second balance drops below 80% of the home's value, at which point a single new loan may no longer require PMI either. Whether that refinance is worth its own closing costs is a separate break-even calculation.
Related reading
- Is Single-Premium PMI Cheaper Than Monthly PMI? One $350,000 Loan, Followed to Cancellation
- Pay Down Principal to Drop PMI Early, or Invest That $10,000 Instead? The Real Math
Tip: Comparing a piggyback loan with PMI is easier when you track the real monthly numbers, so a budget planner or a financial calculator can help you test your own loan scenarios. (These are Amazon Associate links — we may earn a small commission on qualifying purchases.)
Correction November 12, 2026: The Year 8.6 row of the cost table counted only the first-mortgage balance ($284,099) in Path A and left out the second mortgage's remaining balance after 103 payments ($7,851 on the $40,000, 8.268%, 10-year loan). Path A's remaining debt is $291,950, its total is $565,805 and the B-minus-A gap at that point is $54,130, not $61,981. Recalculated with standard amortization from the loan terms stated in this article; the 1-, 3- and 5-year rows were rechecked and are unchanged.
Sources
- Primary Mortgage Market Survey (PMMS), week of November 5, 2026 — Freddie Mac
- Home equity and HELOC rate averages, as of November 4, 2026 — Mortgage Research Center data via Fortune
- Genworth borrower-paid PMI rate card by LTV, coverage and credit score — ValuePenguin
- Homeowners Protection Act (HPA) / PMI Cancellation Act examination procedures — Consumer Financial Protection Bureau
This article is general information for educational purposes, not personalized financial, tax or legal advice. Mortgage and insurance rates change; confirm current figures with your own lender and insurer before making a decision.
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