What Is a HELOC? Draw Period, Payment Shock, and How It Works

A HELOC — short for home equity line of credit — is a revolving loan secured by the equity in your home. It works like a credit card with a spending limit set by your equity: during a draw period (typically 10 years) you can borrow, repay, and re-borrow up to your limit, and during a repayment period (typically 20 years) the balance converts to a fully amortizing loan and you can no longer draw. Because a HELOC is secured by your house, rates are lower than credit cards or personal loans — but the tradeoffs are significant. Rates are almost always variable (tied to the prime rate), your monthly payment can jump when the draw period ends, and missed payments can lead to foreclosure. This guide is the mechanics-and-risks deep dive; for a shorter overview that weighs borrowing against selling, see what is a HELOC loan. The Consumer Financial Protection Bureau describes a HELOC as an open-end line of credit that a lender secures by taking a lien on your home, and that framing — line of credit, lien on the house — is the key to understanding how the product behaves in the good years and in the bad.

Key Takeaways

• A HELOC is a revolving line of credit secured by your home equity, split into a draw period and a repayment period.
• Most HELOCs carry a variable rate — typically the prime rate plus a lender-set margin — so payments can rise if the Fed raises rates.
• Typical structure: 10-year draw period with interest-only payments, then a 20-year repayment period with principal plus interest.
• Payment shock is the number-one HELOC risk: at the same rate, the interest-only → amortizing step-up is often about 20–25%; if rates rose during the draw period, the jump can reach ~35% or more overnight.
• HELOC interest is only tax-deductible if the funds were used to buy, build, or substantially improve the home securing the loan, per the Tax Cuts and Jobs Act (TCJA).

What Is a HELOC?

A HELOC is a second mortgage in the form of a revolving line of credit. Instead of receiving a lump sum, you get access to a credit line up to a limit the lender sets based on the equity in your home. You can draw funds during the draw period, repay what you borrow, and draw again — the same way a credit card works — except the collateral is your house rather than an unsecured promise to pay.

The word "line" matters. A traditional second mortgage in the form of a home equity loan gives you the entire amount up front, and you begin repaying principal and interest immediately. A HELOC gives you a ceiling and only charges interest on what you actually draw. If your line is $80,000 and you draw $15,000 for a bathroom remodel, you only pay interest on the $15,000 — the other $65,000 sits available but does not accrue any charge.

Because the loan is secured by a lien recorded against your property — the same mortgage note and lien recording mechanism used for a first mortgage — the lender can foreclose if you fall behind on payments. That is why a HELOC's rate is dramatically lower than an unsecured credit card: the lender's downside risk is limited by the value of your home.

How a HELOC Works: Draw Period vs. Repayment Period

Every HELOC has two distinct phases, and they behave very differently. Understanding the transition between them is the single most important thing a borrower can learn before signing.

The draw period

During the draw period — usually 10 years — you access funds by check, debit card, online transfer, or a wire request. Most HELOCs require interest-only payments on the outstanding balance. If you draw $30,000 at 8.5%, your monthly interest-only payment is roughly $30,000 × (8.5% ÷ 12) ≈ $213.

You can pay more than the minimum, and doing so pays down principal, which frees up more credit. You can also carry a balance right up to your limit. The line is dynamic — it moves with your draws and repayments.

At the end of the draw period, the line freezes. No new advances are allowed. Whatever balance is outstanding becomes the balance you must fully repay during the repayment period.

The repayment period

Repayment lasts about 20 years on a standard HELOC. The remaining balance amortizes — meaning each monthly payment now includes principal plus interest, calculated to bring the loan to zero by the end of the term. Because the rate is variable, your payment can shift over time as the prime rate moves.

This transition is where borrowers get hurt. A borrower paying $213 in interest-only during the draw suddenly owes a fully amortizing payment on a $30,000 balance over 20 years — roughly $260 per month at the same rate. On a $100,000 balance, the jump is from $708 interest-only to about $868 fully amortized at the same rate — and much more if the prime rate has drifted higher during the decade in between. This is what the CFPB calls the end-of-draw payment shock in its consumer HELOC booklet.

How HELOC Interest Rates Work (Prime + Margin)

Almost all HELOCs are variable-rate loans. The rate is calculated as an index plus a margin:

HELOC rate = Index + Margin

• Index: Almost always the Wall Street Journal prime rate, which tracks the Federal Reserve's H.15 Selected Interest Rates release and moves in lockstep with the federal funds target. When the Fed raises rates by 25 basis points, prime typically rises 25 basis points a day later.
• Margin: A fixed spread the lender sets based on your credit profile — usually somewhere between −0.50 percentage points (for very strong borrowers) and +3.00 percentage points (for weaker profiles). Margins are set at origination and generally do not change.

If prime is 7.50% and your margin is +0.50%, your HELOC rate is 8.00%. If the Fed raises rates and prime moves to 8.00%, your rate becomes 8.50% — and your payment adjusts accordingly. Many HELOCs allow the rate to reset monthly, so payment changes can arrive quickly.

This mechanic differs from a standard first-mortgage rate, which is usually fixed for the life of the loan. Readers who want to compare how variable and fixed rates behave should read how mortgage rates work. A HELOC is the mirror image of the fixed-rate product you get when buying down your rate on a purchase mortgage — the rate moves with the market, for better or worse.

Some lenders offer fixed-rate HELOC conversion options, which let you lock a portion of your outstanding balance at a fixed rate during the draw period. These features vary widely and often carry a fee, but for borrowers who want to hedge a large draw, they are worth asking about.

Rate caps

Federal Regulation Z (Truth in Lending Act) requires HELOCs to disclose a lifetime cap — the maximum rate the loan can ever reach. Caps are frequently set at 18% by statute in many states, but some lenders set them lower. There is often no periodic cap on how much the rate can rise between adjustments, which is very different from most adjustable-rate first mortgages.

Typical HELOC Terms and Structure

While HELOCs vary lender to lender, most follow a recognizable pattern:

• Draw period: 10 years (some lenders offer 5 or 15)
• Repayment period: 20 years
• Combined loan-to-value (CLTV) cap: 80–85% at most HELOC lenders. Fannie Mae's first-mortgage rules for subordinate HELOCs are in B2-1.2-02 (CLTV), B2-1.2-03 (HCLTV), and B2-1.2-04 (subordinate financing); 85% CLTV is the common industry ceiling for a first-lien plus HELOC.
• Minimum initial draw: Often $10,000–$25,000 at closing
• Minimum subsequent draw: $100–$500 per transaction
• Closing costs: Usually 2–5% of the credit line; some lenders waive them but charge an early-termination fee if you close the line within 24–36 months
• Annual fee: $50–$100 in some cases
• Inactivity fee: Some lenders charge if the line goes unused for 12 months

Because the credit line is set at origination but can be drawn against for a decade, lenders reserve the right to freeze or reduce the line if your home value drops or your credit profile deteriorates. This happened widely during the 2008 downturn and is disclosed in every HELOC agreement.

HELOC vs. Home Equity Loan vs. Cash-Out Refinance

Borrowers frequently confuse the three main equity-borrowing products. Here is how they differ:

The CFPB's side-by-side comparison walks through the disbursement and interest differences in plain language. The choice usually comes down to three factors: whether you know the total cost of what you are funding, how you feel about rate risk, and whether your existing first-mortgage rate is low enough to preserve.

A cash-out refinance replaces your first mortgage entirely and gives you the difference in cash. If your existing first-mortgage rate is, say, 3.25% from a 2021 refinance, cashing out means giving up that rate on the entire balance and re-borrowing at today's higher rate. A HELOC lets you keep the low first-mortgage rate and only borrow at market rates on the new draw — often a much cheaper outcome even though HELOC rates are higher than 30-year fixed rates.

How to Qualify for a HELOC

HELOC underwriting looks a lot like a first-mortgage underwriting — but stricter, because the lender sits in a junior lien position.

• FICO score: Most mainstream lenders want 680+ for standard approval and the best margins. Some portfolio lenders will go into the mid-600s with tighter CLTV caps and higher pricing.
• Debt-to-income ratio (DTI): Usually 43% or below, counting both your first-mortgage payment and the projected HELOC payment. This is the same 43% DTI benchmark used across most mortgage underwriting.
• Combined LTV (CLTV): Typically capped at 80–85%. This is where equity math matters — you need to know your home's current appraised value and subtract your first-mortgage balance to see how much of the ceiling is left.
• Verifiable income: W-2s, recent pay stubs, tax returns for the self-employed, and bank statements. A gap in employment can slow underwriting.
• Homeowners insurance: Required, with the lender named as an additional loss payee.

The equity math

To estimate the maximum credit line, use:

Maximum HELOC = (Appraised value × Max CLTV) − First-mortgage balance

On a home appraised at $500,000 with $300,000 remaining on the first mortgage and an 85% CLTV cap: $500,000 × 0.85 = $425,000 − $300,000 = $125,000 maximum line.

If little equity remains after the HELOC, the lender may still approve the line but will usually price it higher and tighten the CLTV cap — HELOCs are second liens and do not carry conventional private mortgage insurance (PMI). Keeping combined balances below ~80% CLTV still matters for pricing and future refinance flexibility, the same equity threshold that lets conventional first-lien borrowers request PMI removal.

You can work with any licensed mortgage lender of your choosing — Opendoor does not originate HELOCs. Credit unions, community banks, and large national banks all compete for HELOC business, and margins vary meaningfully across lenders. Shopping three to five quotes is standard.

What Does a HELOC Payment Look Like?

Two of the most-searched HELOC questions are variations of "what is the monthly payment on a $50,000 HELOC?" and "how much is a HELOC payment on $100,000?" The answer depends heavily on which phase you are in and where the prime rate sits. Here are worked examples at an 8.5% rate (roughly prime + 0.5% in a moderate-rate environment):

At the same rate, the amortization step-up looks modest. The real payment shock arrives when the rate has moved. If prime rose 2 percentage points during the draw period (from 7.50% to 9.50%), your HELOC rate would be 10.0% instead of 8.5% — and the $100,000 balance amortizing over 20 years jumps from $868 to $965 per month. Combine that with the loss of interest-only payments and a borrower who was paying $708 during the draw is now paying ~$965 in repayment. That is a 36% payment increase, essentially overnight.

Interest-only payment formula for the draw period is simple: balance × (annual rate ÷ 12). The amortizing repayment formula is the standard mortgage payment formula applied over 20 years (or whatever your specific repayment term is).

Common Uses for a HELOC

HELOCs are best suited to phased spending or projects with an uncertain total cost. The classic use cases:

• Home renovation. The best case. Draws are staged to match contractor progress payments, and if the money is used to buy, build, or substantially improve the home securing the loan, the interest can be tax-deductible (see TCJA discussion below). Renovation also tends to add to equity, offsetting the leverage.
• Debt consolidation. Rolling high-interest credit-card balances (often 20%+ APR) into a HELOC at, say, 8.5% saves interest. The catch: you are converting unsecured debt into debt secured by your house. Missing a HELOC payment can lead to foreclosure; missing a credit card payment cannot.
• Emergency reserve. Some homeowners open a HELOC and leave it undrawn as a standing line of credit for unexpected medical bills, job loss, or major repairs. Because a HELOC costs little when unused (only annual or inactivity fees, if any), it can be cheaper than carrying a large cash cushion.
• Education expenses. Tuition or private-school costs can be funded via HELOC, but federal student loans usually offer better protections and deferment features.
• Investment property down payment. Some investors tap primary-residence equity to buy a rental. This concentrates risk — a rental-market downturn now threatens your primary home.

Skip the HELOC for vacations, weddings, vehicles, or any spending that depreciates. The interest rate is lower than a credit card, but the collateral is your house.

HELOC Risks: Payment Shock, Rate Volatility, and Foreclosure

Bank product pages tend to bury the risks. Here are the three that matter most.

Payment shock at the end of the draw period

This is the risk borrowers most consistently underestimate. During the draw period, most HELOCs require interest-only payments — which means when repayment starts, you are amortizing whatever balance you carried into repayment over 20 years. At a stable rate, that step-up is often about 20–25% (see the payment table above). Combined with a variable rate that rose during the decade of the draw, the overnight jump can reach ~35% or more — still painful cashflow shock, even when it is not a full 2× cliff.

The CFPB flagged end-of-draw payment shock as a systemic risk in its HELOC consumer booklet after the 2008 downturn, when a wave of HELOCs originated in the early 2000s transitioned to repayment and many borrowers could not afford the new payments.

Rate volatility

Almost all HELOCs are variable-rate. When the Fed hikes, your rate hikes — usually within a month. The lifetime cap protects against catastrophic increases (most caps are 18%), but the day-to-day risk is real. A $100,000 balance at 8.5% interest-only is $708 per month. At 12% interest-only it is $1,000. A 350-basis-point move over a decade is not extreme by historical standards.

Foreclosure risk

A HELOC is secured by a lien recorded against your property. If you default, the HELOC lender can foreclose, though because it sits in second-lien position it may recover less than the first-mortgage holder. The CFPB's foreclosure guide walks through the process. State laws vary — some are judicial foreclosure states, others allow non-judicial foreclosure that moves much faster.

If you fall behind, contact the lender immediately. Loss-mitigation options exist, and options like mortgage forbearance can sometimes buy time. Early communication matters more than any single financial move.

Line freeze risk

Lenders reserve the right to freeze or reduce the line if your home value drops or your credit deteriorates. If you were relying on the HELOC as an emergency reserve, the emergency itself may cause the reserve to disappear. This risk is disclosed in every HELOC agreement but is easy to overlook.

What Happens at the End of the Draw Period

At the end of the draw period — usually the 10-year anniversary of your HELOC — three things happen:

• The line freezes. You cannot draw any more funds. If you had an available balance you had been treating as a reserve, that reserve disappears.
• The balance converts to fully amortizing. Whatever principal you owe on that anniversary is scheduled to be paid off over the repayment term (usually 20 years).
• The payment resets. You now owe principal plus interest, calculated at your then-current variable rate. This is where payment shock hits.

Some HELOCs offer a balloon structure instead of amortized repayment — meaning the entire balance is due on a single date at the end of the draw period. Balloon HELOCs are less common today but do exist, particularly with community banks. Read your agreement carefully for the words "balloon payment" or "single payment due."

You have a few options if you are staring at the end of a draw period with a large balance:

• Refinance the HELOC into a new HELOC (extending the draw)
• Roll the balance into a fixed HELOAN for payment certainty
• Do a cash-out refinance on the first mortgage to absorb the HELOC balance
• Pay it off from savings if you can
• Sell the home and pay off both liens at closing

The right move depends on your first-mortgage rate, your appetite for rate risk, and how much of the balance you can realistically pay down.

Is HELOC Interest Tax-Deductible?

Under the Tax Cuts and Jobs Act (TCJA) — originally enacted for tax years 2018–2025 and extended by the 2025 tax package (OBBBA), so the framework still applies for tax year 2026 — HELOC interest is deductible only if the loan proceeds were used to buy, build, or substantially improve the home that secures the loan. Interest on HELOC funds used for anything else — debt consolidation, tuition, medical bills, vacations — is not deductible.

The IRS clarified this rule in IRS FAQ: Interest on Home Equity Loans Often Still Deductible Under New Law. The full technical rules are in IRS Publication 936.

Three additional constraints apply:

• You must itemize. The deduction is only useful if your total itemized deductions exceed the standard deduction. For tax year 2026, that is $15,750 single / $31,500 married filing jointly per IRS Rev. Proc. 2025-32. Most taxpayers do not itemize post-TCJA.
• The debt cap is $750,000. For loans originated after December 15, 2017, the combined balance of first-mortgage debt plus deductible home equity debt eligible for the deduction is capped at $750,000 ($375,000 if married filing separately).
• The funds must be traceable to the home. If you draw $50,000 for a kitchen remodel and $30,000 to pay off credit cards, only the interest attributable to the $50,000 renovation portion is deductible. Keep contractor invoices and canceled checks.

Consult a tax professional. The 2025 tax package (OBBBA) extended the TCJA framework beyond its original 2025 expiration, but Congress may modify the rules in future sessions. Do not rely on general guidance for a specific tax filing.

How to Close or Pay Off a HELOC

Closing a HELOC is different from paying off a first mortgage because of the revolving nature. Here are the main paths:

• Pay to zero and request formal closure. Paying the balance to zero does not automatically close the account. You need to send the lender a written request to close the line and release the lien. Get written confirmation.
• Refinance into a fixed home equity loan. Locks in a payment and eliminates rate volatility. Best when you have a stable balance and want certainty.
• Roll into a cash-out refinance. Replaces your first mortgage with a larger one that absorbs the HELOC. Best when the rate environment favors refinancing your first mortgage anyway.
• Sell the home. Both liens are paid at closing from sale proceeds — same mechanism as for any paying off your mortgage early situation on a first mortgage.

Watch out for early-termination fees. Many lenders waive HELOC closing costs at origination but reimpose them (often $300–$600) if you close the line within the first 24 to 36 months. Check the agreement before you accelerate a payoff.

Also confirm that the lender files a lien release with the county recorder after payoff. An unreleased lien can complicate a future sale or refinance. If a release does not appear on your title report within 60–90 days, follow up with the lender.

Alternatives to a HELOC

A HELOC is not the only way to tap equity, and it is not always the best fit.

• Home equity loan (HELOAN). A lump-sum, fixed-rate second mortgage. Best when you know the exact amount you need and want payment certainty. Rates are usually 0.5–1.5 percentage points higher than HELOC starting rates but do not move.
• Cash-out refinance. Replaces the first mortgage with a larger one and gives you the cash difference. Best when your current first-mortgage rate is at or above market and you want a single loan.
• Personal loan. Unsecured, no lien on the home, faster closing. Rates are much higher (typically 10–18%) but you are not risking foreclosure.
• 0% APR balance-transfer credit card. For small, short-term needs where you can pay off the balance during the promotional period (usually 12–21 months). Transfer fees typically run 3–5%.
• Reverse mortgage (HECM). Available to homeowners 62 and older. Converts equity into cash without monthly payments — but interest compounds against the balance and the loan is repaid when the home is sold or the borrower dies or moves out.
• 401(k) loan. Borrow from yourself. No credit check, no home as collateral — but leaving your job typically triggers a full-balance repayment demand within 60–90 days.
• Sell the home. The cleanest way to access equity — no lien, no interest, no risk. Only makes sense if you were already considering a move.

Disclosure

Opendoor Home Loans LLC is not available in all markets. Products, programs, rates, and terms are subject to change without notice. This material is provided for informational purposes only and is not an offer or guarantee of credit. Opendoor Home Loans does not currently originate HELOCs — the content above is educational. Contact Opendoor Home Loans for current availability of products offered.