Refinance a Second Mortgage or HELOC: Options and Rules

How to refinance a second mortgage: your options, subordination, and combining loans

Published November 4, 2026 · 8Twelve Mortgage

You have three main ways to refinance a second mortgage. You can replace the home equity loan or HELOC with a new second lien, combine it with your first mortgage into one new loan, or keep it in place while you refinance only the first, which needs the second-lien holder to sign a subordination agreement. Lenders look at your combined loan-to-value, credit and income. Combining the loans can also turn the refinance into a cash-out loan, and that changes the limits.

What counts as a second mortgage

A second mortgage is any loan secured by your home that sits behind your main mortgage. If you sell or default, the first mortgage is paid before the second. The two common types are:

Home equity loan. A lump sum with a fixed repayment schedule. See home equity loans.
HELOC. A revolving line you draw on during a draw period, followed by a repayment period. Most have variable rates. See HELOCs.

Some buyers also have a second lien from the purchase itself, such as a piggyback loan used to cover part of the down payment. That detail matters later, because lenders treat purchase-money seconds differently.

Your three refinance options

Refinance the second on its own. Replace the HELOC or home equity loan with a new second lien and leave your first mortgage alone. This often suits homeowners whose first mortgage has terms they want to keep, or who want to swap a variable HELOC for a fixed payment.
Combine both loans into one. A new first mortgage pays off the existing first and second. You get one payment and one rate, but you give up your current first mortgage and its terms.
Refinance the first and keep the second. The second stays open, and its lender agrees to stay behind the new first loan through subordination.

How subordination works

Liens are usually ranked by the date they were recorded. When you pay off your first mortgage with a new loan, your existing second would move into first position unless its lender agrees to step back. A subordination agreement is that promise, and your new first-mortgage lender will require it before closing.

Ask your refinance lender early whether they need a subordination, and send the request to your second-lien holder right away
The second-lien holder isn't required to agree and may set conditions, such as a maximum combined loan-to-value
Expect a review period and possibly a fee; delays here can push back your closing date
If the second-lien holder says no, your options are usually to pay off the second or combine both loans

When combining loans counts as cash-out

How the lender classifies your refinance affects how much you can borrow and how the loan is priced. Under Fannie Mae's Selling Guide, a limited cash-out (rate-and-term) refinance can generally pay off a second lien only when that second was used to buy the home, or when it's a HELOC with little recent borrowing. Paying off other seconds, such as a home equity loan taken years after purchase, usually makes it a cash-out refinance.

Cash-out refinances often come with lower loan-to-value limits and their own waiting periods. Other programs, like FHA and VA, set their own rules. See cash-out refinancing for how those loans work.

What lenders check

Combined loan-to-value. All loans secured by the home, divided by its current value. For a HELOC you keep, lenders often count the full credit limit, not just the balance.
Credit. Your score and your payment history on both loans.
Income and debts. The new payments have to fit within the lender's debt-to-income limits.
Home value. An appraisal or automated valuation, depending on the lender and loan size.
Payoff terms. Check both loans for prepayment penalties or early-closure fees before you apply.

How to decide which route fits

If your first mortgage has terms you'd rather keep, refinancing only the second usually protects them
If your HELOC is nearing the end of its draw period, plan the move before the payment changes, using the dates in your HELOC agreement
If both loans carry terms you'd like to replace and you have the equity, one combined loan can simplify things
Compare total costs, not just the monthly payment: closing costs and a longer term can outweigh a lower payment

Run the numbers with our refinance calculator guide, and see refinance costs for what goes into closing costs.

Sources

Consumer Financial Protection Bureau guidance on home equity lines of credit, refinancing and the Loan Estimate; the Fannie Mae Selling Guide sections on limited cash-out and cash-out refinance transactions and subordinate financing. Program rules change, and your lender applies the version in force when you apply.

Before you apply

8Twelve is a mortgage broker, not a lender. We look at both of your loans, check whether your refinance would be treated as cash-out, handle the subordination request if you keep your second, and compare lenders in our network.

Frequently asked questions

Can you refinance a second mortgage?

Yes. You can usually replace a home equity loan or HELOC with a new second lien, or pay it off by combining it with your first mortgage in a single new loan. Which route fits depends on your equity, your credit, the terms on your first mortgage, and whether you need to keep the second line open.

Can I combine my first and second mortgage into one loan?

Often, yes, as long as the combined balance fits within the lender's loan-to-value limit and you qualify for the new payment. One loan means one payment and one rate. It also means replacing your first mortgage, so compare the new terms with what you have now, especially if your current first mortgage carries a low rate.

Is paying off a second mortgage in a refinance considered cash-out?

It can be. Under Fannie Mae rules, a limited cash-out (rate-and-term) refinance can generally pay off a second lien only if it was used to buy the home, or if it's a HELOC with little recent borrowing. Paying off other seconds usually makes the refinance a cash-out transaction, which can mean a lower loan-to-value limit and different pricing. Ask the lender how your loan will be classified.

What is a subordination agreement?

When you refinance your first mortgage and keep your second, the new first loan has to stay in first position. The second-lien holder signs a subordination agreement agreeing to stay behind the new first mortgage. The second-lien holder isn't required to agree, and may charge a fee or take a few weeks to review the request.

Should I refinance my HELOC before the draw period ends?

It's worth planning ahead. When the draw period ends, most HELOCs move into repayment, and the payment usually rises because you start repaying principal. Your HELOC agreement shows when that happens. Options include refinancing into a fixed-rate home equity loan, folding the balance into a new first mortgage, or asking your lender about a new line.

Do I need an appraisal to refinance a second mortgage?

Usually some kind of valuation is needed, because lenders size the loan on your combined loan-to-value. Depending on the lender and the loan amount, that may be a full appraisal or an automated valuation. Your Loan Estimate will list any appraisal fee.