A Personal Note Before We Dive In
As someone who has lived all over Austin—and even bought, sold, and bought again all within the same year—I’ve seen firsthand how today’s mortgage environment shapes people’s mobility.
I love this city and I love helping people find the right pocket of Austin that feels like home. But I also feel what every homeowner with a 2–3% rate feels right now: the hesitation, the math, the frustration, the “I’d move… but not if it means doubling my interest rate.”
That’s why this topic matters.
Not in theory.
Not in policy talk.
But in real life, for real homeowners.
— Dave Bunyea
What Is a Portable Mortgage?
A portable mortgage allows a homeowner to take their existing mortgage—and its interest rate—to a new property when they move, rather than taking out a brand-new loan.
This concept isn’t new globally, but it is new to U.S. housing policy. Recently, FHFA Director Bill Pulte confirmed that the Trump administration is “actively evaluating portable mortgages” as a way to improve affordability and unlock inventory.
Today, more than half of U.S. homeowners have a rate below 4%, but average mortgage rates remain between 6%–7%. Many people are staying put—not because they don’t want to move, but because they’re unwilling to trade a 3% rate for a 6.5% one.
This “I’d move… but not at that rate” dilemma is known as the lock-in effect, and portable mortgages aim to break it.
How a Portable Mortgage Works
Portable mortgages let you transfer the remaining balance and interest rate on your current mortgage directly to a new home.
Example:
You sell your home for $400,000
You still owe $200,000 at a 3% interest rate
You move that same $200,000 mortgage to your next home and keep the 3% rate
But What If Your New Home Costs More?
If the next home is $450,000, you’d cover the extra $50,000 using:
- Cash
- A second, smaller loan (likely at current rates)
This results in a blended solution—part at your original rate, part at today’s rate.
Why Portable Mortgages Are Being Considered Now? Housing affordability is the #1 concern across U.S. metros, including Austin.
1. They reduce the lock-in effect
Homeowners with ultra-low pandemic-era rates have little incentive to move.
Portability changes the equation.
2. They could increase housing supply
More freedom to move = more listings = more pathways for buyers.
3. They expand options in a tough market
With median home prices around $415,200 and rates above 6%, buyers need alternatives.
4. They offer flexibility without the downsides of a 50-year mortgage
The proposed 50-year mortgage received criticism for ballooning lifetime interest.
Portable mortgages are seen as a less risky innovation.
But Could Portable Mortgages Backfire? Experts say yes—it’s possible.
1. Mortgage-backed securities could be disrupted
Investors expect loans to be paid off when homes sell.
If mortgages last longer, investors may demand higher rates, raising borrowing costs.
2. Mortgages are legally tied to specific properties
Every loan lists a specific address as collateral. Transferring that contract to a new home is a massive legal hurdle. Mortgage banker Justin Demola called it “a logistical nightmare.”
3. It could push home prices higher
If more homeowners can move easily, demand could spike. As CEO Kevin Thompson put it: “If you open the market, homeowners with massive equity can port their low-rate mortgages and use that equity to bid up prices elsewhere.”
4. It doesn’t fix the real problem: inventory
Even if sellers list, they still need somewhere to go.
Unlike Austin, most of the U.S. has a supply challenge at its core.
