The Quick Read: Usually yes, when your jumbo first mortgage costs well below today’s market, the cash you need is small next to that balance, and you qualify personally for a second lien, because keeping the first loan reprices only the new money instead of the whole balance. The catch is that the new line floats in price, can be frozen or reduced, and has tighter limits on a rental than on your own home.
- A cash-out refinance replaces your whole balance at today’s pricing. A line prices only what you draw.
- Across our wholesale network, an investment-property line tops out at 70% combined loan-to-value and $500,000, with a 700 minimum credit score, subject to lender guidelines.
- At least 75% of the line is drawn at closing, so it is not an idle backup account.
- The borrower must hold title personally or in a revocable living trust. An LLC-owned rental points to a DSCR cash-out refinance instead, subject to lender program eligibility.
- Large cash needs, entity title, or a wish to qualify on rent all favor the DSCR route.
Key Terms Defined
You will see a few terms repeatedly. Here is each one, once.
- Jumbo loan: a mortgage above the conforming limit. The baseline one-unit limit is $832,750, and the high-cost-area ceiling is $1,249,125, according to Orrick’s summary of the FHFA announcement.
- HELOC: a home equity line of credit. It is a revolving credit line secured by property equity.
- Second lien: a loan that sits behind your first mortgage in repayment priority. A first mortgage left in place is not changed by it.
- CLTV: combined loan-to-value, meaning all loans on the property divided by its value.
- Draw period: the stretch when you can borrow from the line, often with interest-only payments.
- Repayment period: the stretch after the draw period, when the balance must be paid down.
- DSCR: debt service coverage ratio. It compares a property’s rent to its monthly obligation.
- PITIA: principal, interest, taxes, insurance, and any association dues. This is the obligation DSCR uses.
- Subordination: an agreement where a lender lets another loan sit ahead of its own.
How large a line the equity supports.
An equity line is sized by combined loan-to-value, occupancy, and credit — not by rental coverage. Switch the occupancy or the credit band and the ceiling moves with it.
Investment-property lines require a 700 minimum credit score; second-home lines start at a 640 minimum and primary-residence lines at 600, and the combined-LTV ceiling steps down as the credit band drops on primary-residence and second-home lines and holds on investment-property lines; the line cap steps down on primary-residence lines and holds at every tier on investment-property and second-home lines.
A debt-to-income ratio above 45% requires 680+ credit. Profiles under 640 are limited to single-family homes. At least 75% of the approved line is drawn at closing. Ceilings, floors, and caps update from Lendmire’s centralized guideline source.
Line estimate
Illustrative estimate only — not a quote, Loan Estimate, approval, or commitment to lend. The rate is an editable assumption; equity-line pricing is variable through both the draw and repayment periods and never converts to fixed. Occupancy and credit drive the ceiling together: an investment property tops out at 70% combined LTV (minimum credit 700, line cap $500,000); a second home tops out at 90% combined LTV (minimum credit 640, line cap $500,000), with the ceiling stepping down as the credit band drops (the cap holds at every tier); a primary residence tops out at 90% combined LTV (minimum credit 600), and its $750,000 maximum line is available only at 75% combined LTV or below with a 700-or-better credit profile (720 on the longer-runway program) and a full appraisal. Lines above $500,000 require a full appraisal. Credit, debt-to-income, property type, and full underwriting review all affect the final line.
What Does “Keeping” the Jumbo First Mean?
It means the first loan stays exactly as written. Its balance, term, and payment do not change. You add a separate line behind it and borrow only what you need.
A cash-out refinance does the opposite. BiggerPockets explains that a cash-out refinance pays off your existing mortgage and replaces its terms. A HELOC is a second mortgage that leaves the first alone.
Keeping the first loan does not make it invisible. It still counts toward your debt-to-income ratio and toward combined leverage. A big first balance can leave very little room for a second lien. More on that below.
The line can also sit on a different property. Many investors borrow against their own home to fund a rental purchase. The line is secured by that home, and the cash goes wherever you need it.
Why Is the Low-Cost Debt Worth Protecting?
Because a refinance reprices every dollar you owe, while a line reprices only the new money. On a jumbo balance, the whole-balance repricing is the expensive part. The bigger the first loan, the more you give up by touching it.
Plenty of owners hold cheap debt. Redfin’s analysis of federal housing finance data found that 52.5% of outstanding mortgages sat below 4%, and 20.4% sat below 3%. That is market context, not a read on your own loan.
CBS News reports that when your existing pricing sits well below current averages, refinancing may be counterproductive. The same piece notes that HELOC pricing is variable. Both halves matter.
The Blended-Cost Picture
Here is a modeled scenario, using percentages only. Say you need new cash equal to 10% of your total borrowing after the draw. The other 90% is your existing jumbo balance.
| Factor | Keep first + HELOC | Refinance everything |
|---|---|---|
| Share repriced | About 10% of debt | 100% of debt |
| New-money pricing | Floats | Fixed or floating, your choice |
| Fee base | The line amount | The full loan |
| Term reset | None on the first loan | Yes, a new term starts |
The keep-the-first path wins when the repriced share is small. It loses ground as the draw grows. If the new money approaches the size of the old balance, the refinance becomes the more reasonable comparison. It also reverses if today’s market pricing has fallen below what your first loan costs.
How Much Room Does a Big First Mortgage Leave?
Often less than people expect. Line room is roughly your property value times the CLTV cap, minus the first-lien balance. A jumbo first uses up a large slice of that room before you start.
Market surveys report that lenders usually ask investors to leave 20% to 35% of equity untouched, which puts borrowing near 70% to 75% of value including the first mortgage, per BiggerPockets. On our network, an investment-property line tops out at 70% CLTV. That is the figure that applies here.
Run it with percentages. If your first lien is 60% of the rental’s value, 10% of value remains under the 70% cap. If it is 65%, only 5% remains. Pricing and available terms vary by lender, borrower profile, property type, and full underwriting review.
Your own home often has more room. Across the network, the ceiling on a primary residence or second home reaches 90% CLTV, but only at a 720 credit profile or better, on lines up to $500,000. Lower credit tiers step down from there. A line above $500,000 is primary-residence only and requires 700 or better (720 on the 5-year-draw structure). It also caps at 75% CLTV and requires a full appraisal.
What Do Lenders Check on These Lines?
They check you, not the rent. A HELOC is underwritten on your personal profile. Rental coverage does not decide it the way it does on a DSCR loan. Here is what the wholesale programs we place files with generally look at, subject to lender guidelines and full file review:
- Credit: the minimum is 600 on primary residences, 640 on second homes, and 700 on investment properties. A single-bureau score keyed to the primary wage earner is used.
- Debt-to-income: 50% maximum, with 45% for scores from 600 to 679. The payment is calculated as interest-only on the maximum draw.
- Valuation: lines up to $500,000 ordinarily use an automated valuation. Anything above that needs a full appraisal. You can also ask for one on a smaller line.
- Structure: two draw structures exist on primary residences and second homes. One has a 3-year interest-only draw and a 17-year repayment. The other has a 5-year draw and a 25-year repayment. Investment lines use the 5-year draw and 25-year repayment only.
- Property: single-family, 2-4 units, PUDs, townhomes, and condos, including non-warrantable ones. Manufactured homes, co-ops, condotels, log homes, and commercial or mixed-use properties are not eligible.
- Exposure: you can hold up to three lines. A borrower who owns more than 15 financed properties is not eligible.
- Availability: this HELOC product runs in 16 full-service states. That is narrower than the 41-market DSCR footprint.
Title is the sharpest limit. The borrower must hold title individually or in a revocable living trust. LLCs, corporations, partnerships, and irrevocable, blind, or land trusts cannot. A rental already deeded to an LLC needs a vesting change or a DSCR cash-out.
Self-employed owners with variable income should note that DTI applies here. A DSCR loan works differently. It qualifies primarily on property-level rental income covering the payment, subject to lender guidelines.
The Risks Nobody Explains
The main risks are a floating price, a payment jump at the end of the draw, and a line that can shrink. Each one is manageable if you plan for it.
Floating price. Pricing on these lines floats across both the draw and the repayment period and never converts to fixed. The CFPB’s HELOC brochure notes that a variable-rate plan’s payment can change even if you do not draw more.
The step-up. Interest-only payments do not shrink the debt. When the draw period ends, the full balance starts amortizing. On our investment structure that is a 5-year draw followed by 25 years of repayment. The CFPB brochure says repayment schedules often run ten or 15 years, so the payment jump depends on the exact plan. Read your own agreement.
The line can be frozen or reduced. The CFPB’s print brochure says lenders generally may freeze or reduce a line if the property’s value falls or your finances weaken. An undrawn line is permission to borrow, not committed capital. That matters most in the downturn you would want it for.
Future refinance friction. If you later refinance the first mortgage, the new first-lien lender generally wants the line paid off or subordinated. Whether the line’s lender agrees depends on its terms. Read the first-lien note too, because restrictions on additional liens would come from there.
Here is a quick stress test before you commit:
1. Assume the line’s payment rises meaningfully and see whether you can still carry it.
2. Assume the line is cut to what you have already drawn.
3. Assume the repayment period starts today.
4. Assume your rents dip and a unit sits vacant for a stretch.
If you pass all four, the plan is sturdy. Tax treatment can depend on how the funds are used and how the property is held; investors should keep clear records and speak with a qualified tax professional before relying on any deduction.
When Is Keeping the Low Mortgage the Wrong Move?
When you need a lot of cash, when your rental sits in an LLC, or when the first loan no longer has a pricing edge. In those cases a DSCR cash-out refinance on the rental often fits better.
DSCR loans are designed for non-owner-occupied investment properties. Because they are business-purpose investor loans, they are reviewed differently from a standard owner-occupied mortgage. Our complete DSCR loans guide covers the basics.
Across our wholesale network, a cash-out refinance on a standard long-term rental tops out around 75% LTV. Short-term-rental collateral caps at 70% on a cash-out. About 6 months of seasoning is the common expectation. Loan sizes run up to $3,000,000 on standard programs (smaller balances available through select lenders). Final terms depend on lender guidelines, property type, leverage, and the borrower’s complete credit picture.
Credit expectations vary. A 620 floor exists in parts of the network, most programs want around 660, and 700 or better unlocks the strongest leverage tiers. Reserves are commonly around 6 months of PITIA, though they vary by lender, leverage, and loan size.
Coverage is where the DSCR path differs from a HELOC. A coverage ratio of 1.00 is where many select programs start. A separate select-lender path takes coverage below 1.00, with leverage and terms adjusted. Stronger ratios open better pricing and leverage.
Clearing 1.00 is not the same as positive cash flow. DSCR compares rent to PITIA only. Repairs, vacancy, management, utilities, and capital expenses sit outside the calculation.
The term options are broader too. The spine is the 30-year fixed. Select lenders in the network offer 40-year terms and interest-only periods, and ARM structures exist for investors who want them. For a larger sum, a fixed closed-end loan avoids the line’s freeze risk. Title can be an individual or an entity, depending on program guidelines.
| Factor | Keep first + HELOC | DSCR cash-out |
|---|---|---|
| Reviewed on | Your personal profile | Property rent vs. payment |
| Investment ceiling | 70% CLTV, $500,000 line | Around 75% LTV, standard rental |
| Structure | Floating, never fixed | Fixed spine, other options |
| First loan | Untouched | Paid off and replaced |
Five Questions to Decide
Answer these honestly, then read the result.
1. Is your first loan priced well below today’s market? If no, a refinance may serve you as well.
2. Is the new cash small next to your first balance? If no, price the refinance.
3. Do you hold title personally or in a revocable trust? If no, look at the DSCR route.
4. Could you carry the line if its price rose or it were cut? If no, shrink the draw.
5. Do you have room under the 70% CLTV investment cap, or room on your own home? If no, the line may not fit at all.
Four or five yeses mean keeping the first and adding a line is worth pricing. Two or fewer point to a DSCR cash-out or a different structure.
Frequently Asked Questions
Is a HELOC better than a refinance when my existing mortgage is cheap?
Often, but not always. A line reprices only the money you draw, while a refinance reprices everything. As the draw grows relative to your first balance, or if market pricing falls below your existing cost, the refinance gets stronger. Run both against your balance, draw size, and holding period.
Can I get a HELOC behind a jumbo loan?
Generally yes, if the numbers fit. Nothing about a jumbo balance blocks a second lien. The limits come from combined loan-to-value, your first-lien note, and the new lender’s guidelines. A big first balance can leave little room, especially under the 70% cap on investment lines.
What happens when the draw period ends?
The interest-only phase stops and repayment begins, so the balance starts amortizing. On our investment structure, that means a 5-year draw followed by a 25-year repayment. Pricing keeps floating through repayment, so the payment can still move.
Can I lock part of the line at a fixed cost?
Not on this network. Pricing floats across both the draw and the repayment period and never converts to fixed. If fixed pricing matters to you, a closed-end loan such as a DSCR cash-out refinance is the better comparison.
What if I refinance my first mortgage later?
The line will need to be paid off or subordinated. Subordination is up to the line’s lender, so it is not automatic. Check your agreement before you open the line.
Next Step
If you are considering a home equity line and want to see how the numbers work, Lendmire can help you compare HELOC options based on the property, the equity available, credit profile, combined leverage, and your goals. Lendmire is a broker arranging financing through select lenders in its wholesale network. Programs and figures are subject to lender guidelines and full file review, and nothing here is a commitment to lend. Before you commit to a loan, price the line so you know what it will cost.
About Lendmire
Lendmire (NMLS# 2371349) is a mortgage broker. Home equity lines of credit — on a primary residence, a second home or an investment property — are arranged through wholesale lenders in Lendmire’s 16 full-service states, and every line is underwritten by the lender under its program guidelines. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
Investors who want the broader program framework can review how DSCR loans work.
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Informational only. Not a Loan Estimate, approval, or commitment to lend. Program availability and eligibility are subject to lender guidelines, credit approval, property review, and underwriting.
References
1. Orrick: FHFA conforming loan limits
2. BiggerPockets: cash-out refinance vs. HELOC
3. Redfin: share of mortgages by rate band
4. CBS News: HELOCs vs. cash-out refinancing
6. CFPB HELOC brochure, print version
This article is part of Lendmire’s home equity line of credit program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: Does a HELOC Let You Keep Your Below-Market First Mortgage? · Can You Keep Your Low First Mortgage and Still Tap Equity With a HELOC? · Should You Keep a Low First Mortgage and Add a HELOC for an ADU?
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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Disclosures. The information presented in this article is general market commentary, not financial, legal, or tax advice. Lendmire is a mortgage brokerage (NMLS# 2371349) — not a direct lender or depository institution — and loan placement is subject to lender underwriting. Nothing in this content represents a commitment to lend. Loan terms, pricing, and program availability vary based on borrower qualifications, property characteristics, and state of subject property, and are subject to change at any time. Lendmire complies with Equal Housing Opportunity requirements. Consumer access: nmlsconsumeraccess.org.