Piggyback Loans: The 80-10-10 Structure, Explained

I'm Quentin, and every so often a client asks me about a structure that sounds more complicated than it actually is: the piggyback loan, most commonly set up as what we call an 80-10-10. Let me break down what that means, who it tends to fit, and where the trade-offs actually live.

The structure itself

An 80-10-10 is really just three numbers describing three pieces of a purchase. Eighty percent of the home's price is financed through a first mortgage. Ten percent is financed through a second loan — often a home equity line of credit, sometimes a fixed second mortgage — that sits behind the first. The remaining ten percent comes from you, as a down payment. Add it up and you've covered one hundred percent of the purchase price without putting down a larger amount, and without the first mortgage exceeding eighty percent of the home's value.

That last part is the whole point. When a single mortgage covers more than eighty percent of a home's value, lenders typically require mortgage insurance to protect against the added risk. Structure the financing as two loans instead, keeping the first loan at or below that eighty percent mark, and the mortgage insurance requirement generally goes away — because on paper, no single loan is carrying that higher-risk slice by itself.

Why someone would choose this over just paying PMI

This is the question I get most. Why go through the hassle of two loans and two sets of paperwork instead of just putting down a smaller amount and paying mortgage insurance? A few reasons tend to come up.

Some buyers do the math and find that the combined payment on two loans, one of them relatively small, ends up costing less per month than a single loan plus mortgage insurance would. That's not universally true — it depends on the rate on the second loan, which is often variable and tied to a HELOC structure — but it's true often enough that it's worth running the numbers both ways before deciding.

Other buyers are trying to stay under a specific loan size for reasons that have nothing to do with mortgage insurance at all — keeping the first mortgage in a lower tier, for instance, when the total purchase price would otherwise push a single loan into a different underwriting category.

And some buyers just don't love the idea of paying for mortgage insurance long-term, even though it can eventually be removed once enough equity builds up, and they'd rather structure around it from day one.

Who actually fits this structure

Piggyback loans work best for buyers with strong, well-documented credit and income, because you're essentially qualifying for two loans instead of one, and both lenders are going to look closely at your full financial picture. I don't typically recommend this route to a buyer who's already stretching to qualify for a single loan — adding a second loan into the mix adds complexity and risk that a straightforward first-time buyer with a tighter budget usually doesn't need.

It tends to fit buyers who have the down payment to make the ten percent piece real, who can comfortably handle two monthly obligations instead of one, and who've actually sat down and compared the total cost against a single loan with mortgage insurance rather than assuming the piggyback route is automatically cheaper.

The trade-offs, honestly

Two closings' worth of paperwork, sometimes two sets of closing costs, and a second loan that often carries a rate that can move over time if it's structured as a HELOC. A single loan with mortgage insurance, by contrast, is simpler to manage, and that mortgage insurance can typically be removed down the road once your equity position improves enough, at which point your payment can actually drop without refinancing anything.

There's no universally correct answer here. I've had clients for whom the 80-10-10 saved real money every month. I've had others where, once we ran the comparison side by side, a single loan with mortgage insurance turned out to be the simpler and cheaper path. The only way to know which fits you is to actually run both scenarios with real numbers before you commit to either one.

What I actually walk clients through before they decide

I sit down with two side-by-side scenarios, same purchase price, same buyer, same down payment amount, and price out both routes: the single loan with mortgage insurance, and the 80-10-10 split. I want the client looking at total monthly payment, yes, but also at how each structure behaves over time — how mortgage insurance eventually falls off one path, and how the second loan on the other path behaves if it's rate-variable and market conditions shift. Numbers on day one only tell part of the story; I want clients thinking about year three and year five too, not just their very first payment.

It's also worth asking your loan officer whether the second loan in a piggyback structure is a lump-sum second mortgage with a fixed rate, or a HELOC that can draw and adjust. Those two versions behave very differently over the life of the loan, and conflating them is one of the more common misunderstandings I run into with clients hearing about this structure for the first time.

Bottom line from me

A piggyback loan is a financing structure, not a shortcut and not a trick — it's a legitimate way to avoid mortgage insurance by splitting your financing into two pieces instead of one. It fits buyers with strong credit, real reserves, and the patience to compare it honestly against the simpler alternative. Ask your loan officer to run both numbers side by side before you decide which road to take.