A second mortgage is a loan secured by a home that sits behind the first mortgage in lien priority.
A second mortgage is a loan secured by a home that sits behind the first mortgage in lien priority.
A second mortgage matters because homeowners can borrow against equity without replacing the original first mortgage. That makes it a different strategic choice from refinancing.
It also matters because Lien Priority affects risk. A second mortgage usually carries different pricing and underwriting considerations than the First Lien because it normally stands behind the primary mortgage claim as a Junior Lien.
This page is important because “second mortgage” is a broad structure, not one single product. Many borrowers hear the phrase and think it refers to a special loan program, when it is really the umbrella category that includes common products such as Home Equity Loan, Closed-End Second Mortgage, and Home Equity Line of Credit (HELOC).
Borrowers encounter second mortgages after they already own the home and want to borrow against equity while leaving the first mortgage in place.
The concept becomes practical when comparing home-equity products with refinancing alternatives.
It also appears earlier in the purchase process through structures like Piggyback Loan, where a second mortgage is used alongside the first mortgage from the start instead of being added later.
For later home-equity borrowing, the borrower should also understand Home Equity Application, Home Equity Underwriting, Home Equity Lien, and HELOC Subordination because a second mortgage can affect future refinancing and title work.
A homeowner wants to access equity but keep the attractive rate on the existing first mortgage. The homeowner takes a separate loan secured by the property behind that first lien. That new loan is a second mortgage.
Second mortgage differs from a Cash-Out Refinance because a cash-out refinance replaces the existing first mortgage, while a second mortgage adds a separate loan behind it.
It also differs from Home Equity Line of Credit (HELOC) because HELOC describes a revolving second-lien product, while second mortgage is the broader structural category. A Piggyback Loan is one common purchase-time use of the broader second-mortgage structure.
It also differs from Closed-End Second Mortgage because closed-end second mortgage describes one fixed-advance version of the broader second-mortgage category.
It also differs from a First-Lien HELOC, which uses a revolving line structure in first position rather than junior-lien position.
It also differs from a Subordination Agreement. A second mortgage is the junior lien itself, while a subordination agreement is the document that may be needed if that junior lien is staying in place during a refinance of the first mortgage.