What Happens to the Down Payment When You Assume a Mortgage in Colorado?

When you buy a home with a new mortgage, you put down 3.5% to 20% as a down payment. When you assume an existing mortgage, the math is completely different — and for most buyers, it is significantly more complicated.

Here is what actually happens to the "down payment" in an assumption transaction, why it matters, and how Colorado buyers are covering the difference.

There Is No Standard Down Payment in an Assumption

In a traditional purchase, your down payment is a percentage of the purchase price. In an assumption, what you pay out of pocket is the gap between the purchase price and the existing loan balance.

Example: Purchase price: $480,000
Seller's existing VA loan balance: $310,000
Your gap: $170,000

That $170,000 is what you need to bring to the table. It is not a "down payment" in the traditional sense — it is the difference between what the seller owes and what you are paying for the home. You pay $170,000, you assume the $310,000 loan, the seller walks with whatever equity they get after costs.

Why the Gap Varies So Much

The gap in any assumption transaction depends on two things: when the seller bought, and how much they have paid down.

A seller who bought in 2019 for $350,000 and has been paying for five years might have a loan balance around $300,000. If their home is now worth $500,000, your gap is $200,000.

A seller who bought in 2021 for $420,000 has only been paying for three to four years. Their balance might be $395,000. If their home is worth $490,000, your gap is $95,000.

The smaller the gap, the more accessible the transaction. Large gaps require either significant cash, a second mortgage, or both.

How Colorado Buyers Are Covering the Gap

Cash. If you have the funds, paying the gap entirely in cash is the cleanest solution. You assume the low-rate loan, there is no second lien, and your monthly payment is simply the assumed loan payment. For buyers who have sold a previous home and have equity, this is often achievable.

Second mortgage. Most buyers do not have $150,000 to $200,000 sitting in cash. A second mortgage covers the gap. Second mortgages for assumption transactions typically carry rates between 7% and 9% in early 2026 — higher than the primary loan, but often the gap financing payment is worth it when you factor in the savings on the assumed rate.

Here is a realistic Colorado scenario:

Assumed loan: $350,000 at 2.875%
Monthly payment: approximately $1,453

Second mortgage: $130,000 at 8% over 10 years
Monthly payment: approximately $1,578

Total monthly payment: $3,031

New conventional loan for the same $480,000 home (20% down, 6.875% rate): approximately $2,516 per month — BUT that assumes you have $96,000 in cash for the down payment. If you are financing 90% conventionally, you are closer to $3,100 per month with PMI.

In many scenarios, assumption with a second mortgage beats or matches conventional financing and gives you a much faster payoff on the higher-rate debt.

Combination. Many buyers use partial cash and partial second mortgage. If the gap is $150,000 and you have $75,000 in cash, you take a second for the other $75,000. The smaller second means a smaller monthly payment and faster payoff.

What If the Gap Is Too Big?

Some assumption deals do not pencil. If the home has appreciated aggressively since the seller bought it, the gap can reach $200,000 to $300,000. At that level, the second mortgage payment can eat much of the savings from the assumed low rate.

Do the math before you fall in love with a property. Calculate:

• The assumed loan payment
• The second mortgage payment on the full gap amount (or your portion if you are putting some cash in)
• Your total monthly payment

Then calculate:

• What you would pay on a new conventional loan for the same purchase price (at current rates, with your actual down payment)

If the assumption saves you at least $300 to $400 per month net, it is usually worth the complexity. If the gap financing eats all the savings, a conventional purchase might make more sense — or you negotiate the purchase price down to make the gap smaller.

The Application Process Is Different

In a conventional purchase, your lender approves you for a new loan. In an assumption, the existing servicer approves you to take over the current loan. This is a different process, and it takes longer — typically 45 to 90 days from accepted offer to close, versus 30 days for a conventional purchase.

The servicer will check your credit, income, and debt-to-income ratio using their own underwriting standards. FHA assumptions require the buyer to meet FHA credit guidelines. VA assumptions require the buyer to be creditworthy, but VA status is not required (non-veterans can assume VA loans, with the entitlement constraint noted below).

Getting pre-verified by a lender who has processed assumptions before closing makes the offer process smoother. A servicer approval letter signals to sellers that you can actually close.

The VA Entitlement Note

If you are assuming a VA loan and you are not a veteran, the seller's VA entitlement stays tied to that loan until you pay it off. For sellers who need their entitlement back to buy their next home with VA financing, this can be a dealbreaker. Raise it early.

If you are a veteran, you can substitute your entitlement at closing. This is the cleanest outcome for everyone.

Run the Numbers Before You Decide

The right tool for evaluating an assumption is a side-by-side payment comparison: assumed loan plus gap financing versus new conventional loan with your actual down payment. That comparison tells you whether the deal is worth pursuing.

Browse active assumable listings at assumableguy.com, or contact Ryan Thomson with Keller Williams for a free payment comparison on any property you are considering.

Equal Housing Opportunity.