Reviewed by the Editorial Team · Updated July 10, 2026 · 6 min read
A second mortgage is any loan that takes a second lien behind your existing mortgage, usually structured as a fixed home equity loan or a revolving HELOC, capped around 80-90% combined loan-to-value.
Key takeaways
A second mortgage takes a lien position behind your existing loan, typically structured as a fixed home equity loan or a revolving HELOC.
Combined loan-to-value is usually capped around 80-90%, limiting how much equity can be pulled out on top of the first mortgage.
It lets homeowners tap equity while keeping the original mortgage's rate and term untouched, rather than refinancing the whole balance.
Because it sits behind the first lien, the rate runs higher than a primary mortgage would charge the same borrower.
Lien position
Second, behind your primary mortgage
Two forms
Fixed home equity loan or revolving HELOC
CLTV cap
Roughly 80-90% combined loan-to-value
Best for
Tapping equity without touching the first loan
How a second mortgage works
"Second mortgage" is the umbrella term for any loan secured by your home that sits behind your primary mortgage in lien position. It comes in two main forms.
The two types of second mortgage
Home equity loan
HELOC
Payout
Lump sum at closing
Draw as needed, revolving
Rate
Fixed
Variable, tied to an index
Payment
Fixed principal + interest
Interest-only draw period, then P&I
Best for
One-time, known expense
Ongoing or uncertain expenses
Both a home equity loan and a HELOC let you borrow against your equity while leaving your first mortgage untouched.
Why second-mortgage rates run higher
A second mortgage is riskier for the lender than a first. If you default, the first mortgage gets paid from foreclosure proceeds before the second sees a dollar.
That subordinate position is why second-mortgage rates typically run higher than first-mortgage rates, even for the same borrower and the same credit profile.
CLTV limit
Lenders generally cap combined loan-to-value — your first mortgage plus the second — around 80-90% of your home's value, which sets the ceiling on how much you can borrow.
Who a second mortgage fits
A second mortgage makes the most sense when refinancing the first loan would mean giving up a rate you don't want to lose.
Homeowners with a low first-mortgage rate they want to keep intact
Borrowers funding a known, one-time cost like a renovation or debt payoff
Homeowners who want ongoing access to funds through a revolving line
Anyone with enough equity to stay under the lender's CLTV cap
It's a weaker fit if your first mortgage already carries a high rate — a cash-out refinance that replaces both loans at once may cost less overall.
Second Mortgages: pros and cons
Pros
Taps equity without refinancing your first loan
Keeps a low rate on your original mortgage
HELOC option offers flexible, as-needed borrowing
Interest may be deductible for home improvements
Cons
Second lien means higher rates than first mortgages
Two monthly payments to manage
Home is collateral on both loans
Combined loan-to-value caps limit how much you can pull
Requirements at a glance
Sufficient equity to stay under roughly 80-90% combined loan-to-value
Credit score generally 620 or higher, with better rates above 680
Debt-to-income ratio within the lender's limits including the new payment
A current appraisal to establish your home's present value
Primary mortgage in good standing with no missed payments
It's any loan secured by your home that sits behind your primary mortgage in lien position, most commonly a home equity loan or a HELOC. It lets you borrow against your equity without refinancing or replacing your existing mortgage.
Is a HELOC a second mortgage?
Yes — a HELOC is one of the two main types of second mortgage, along with a fixed home equity loan. A HELOC is a revolving line of credit; a home equity loan pays out as a lump sum.
What are second mortgage rates like?
They typically run higher than first-mortgage rates because the second lien gets paid after the first in a foreclosure, which makes it riskier for the lender. HELOC rates are usually variable; home equity loan rates are usually fixed.
Is a 2nd mortgage a good idea?
html">HELOC) can make sense for a project like a renovation or debt consolidation when the rate beats your alternatives, but it adds a second lien and payment against your home.
How much equity do I need for a 2nd mortgage?
Most lenders want your combined loan-to-value — your first mortgage plus the new second — to stay at or below 80-90% of your home's value.
That typically means you need at least 10-20% equity remaining after the second mortgage closes, though the exact cap varies by lender and loan type.
How much can I borrow on a 2nd mortgage?
The cap is set by your combined loan-to-value limit, typically 80-90% of your home's appraised value across both loans.
Subtract your existing first-mortgage balance from that ceiling, and the remainder — minus lender fees — is roughly what a second mortgage or HELOC can offer.
What can you use a second mortgage for?
Most borrowers use a second mortgage for home improvements, debt consolidation, or major expenses like education or medical bills, since the rate is usually lower than credit cards or personal loans.
Lenders don't typically restrict how you spend the funds, but using home equity for non-essential spending increases the risk to your house.
This guide is general information, not a lending decision. Program rules and dollar limits change — verify current figures with a licensed lender and confirm licensing at NMLS Consumer Access. See all loan types.
No calculator matches that. Try “refinance”, “FHA”, “HELOC” or “amortization”.