A 5/6 ARM is an adjustable-rate mortgage with an interest rate that stays fixed for the first 5 years. After that, the rate can usually adjust every 6 months. The “5” refers to the initial fixed-rate period, and the “6” refers to the six-month adjustment schedule after the fixed rate ends.
The defining feature of a 5/6 ARM is timing. You get 5 years of fixed-rate protection, then the loan can adjust twice per year in many cases. That makes it different from a 5/1 ARM, which usually adjusts once per year after the first 5 years.
5/6 ARM Basics
| Feature |
What It Means |
Why It Matters |
| 5-Year Fixed Period |
Your interest rate is fixed for the first 5 years. |
You get early payment stability before the loan can adjust. |
| 6-Month Adjustment Period |
After year 5, the rate can usually adjust every 6 months. |
Your payment may change more often than it would with an annual-adjustment ARM. |
| Index |
A market-based benchmark rate that can move over time. |
Index changes can affect the adjusted rate after the fixed period. |
| Margin |
A lender-set percentage added to the index. |
The margin helps determine your adjusted rate and can vary by lender. |
| Rate Caps |
Limits on how much the rate can change at the first adjustment, later adjustments and over the life of the loan. |
Caps limit rate movement, but they do not prevent payment changes. |
How a 5/6 ARM Works
A 5/6 ARM has two main phases: the initial fixed-rate period and the adjustable period.
The First 5 Years
During the first 5 years, your interest rate stays the same. Your principal and interest payment is based on that starting rate, assuming you do not refinance, recast, make extra payments or otherwise change the loan.
This fixed period can appeal to borrowers who want early payment stability but do not expect to keep the same mortgage for the full loan term.
After Year 5
After the fixed period ends, the rate can usually adjust every 6 months. That means the first adjustment may happen around year 6, followed by another potential adjustment about 6 months later.
The CFPB’s ARM booklet says borrowers should compare adjustable-rate mortgage features such as how often the interest rate adjusts, the index, the margin, the caps and how high the payment could go.
What the 5 and 6 Mean in a 5/6 ARM
The numbers in a 5/6 ARM describe the timing of the loan’s rate changes.
| ARM Term |
Meaning |
Borrower Impact |
| 5 |
The starting rate is fixed for 5 years. |
Your principal and interest payment is more predictable during the early years. |
| 6 |
The rate can adjust every 6 months after the fixed period. |
Your payment can change more frequently after year 5. |
Always confirm the exact adjustment schedule in your Loan Estimate and closing documents. Some ARMs adjust annually after the fixed period, while others adjust every 6 months.
5/6 ARM vs. 5/1 ARM
A 5/6 ARM and a 5/1 ARM both start with a 5-year fixed-rate period. The difference is how often the rate can change after that period ends.
| Feature |
5/6 ARM |
5/1 ARM |
| Initial Fixed Period |
5 years |
5 years |
| Adjustment Frequency After Fixed Period |
Usually every 6 months |
Usually once per year |
| Payment Change Timing |
Payment may change twice per year after year 5. |
Payment may change once per year after year 5. |
| Main Risk |
More frequent adjustments after the fixed period. |
Less frequent adjustments, but payment can still rise. |
| What To Compare |
Starting rate, margin, caps, six-month adjustment rules and maximum payment. |
Starting rate, margin, caps, annual adjustment rules and maximum payment. |
A 5/6 ARM may be worth comparing if its starting rate or overall pricing is meaningfully better than a 5/1 ARM or fixed-rate option. But the six-month adjustment schedule can make the loan less predictable once the fixed period ends.
How 5/6 ARM Adjustments Are Calculated
After the fixed-rate period, a 5/6 ARM commonly uses this formula:
Index + margin = adjusted rate, subject to caps
The index is the market-based benchmark. The margin is the lender-set percentage added to the index. The CFPB explains that the index can change with market conditions and that the margin can vary between lenders.
For example, if the index is 4.25% and the margin is 2.25%, the fully indexed rate would be 6.50% before applying any caps. If the loan’s caps limit the adjustment, the actual adjusted rate may be lower than the fully indexed rate at that point.
What Rate Caps Mean on a 5/6 ARM
Rate caps limit how much your interest rate can move.
Initial Adjustment Cap
The initial adjustment cap limits how much the rate can change at the first adjustment after the 5-year fixed period ends. This matters because the first adjustment may allow a larger rate change than later adjustments.
Periodic Adjustment Cap
The periodic adjustment cap limits how much the rate can change at each later adjustment. For a 5/6 ARM, this often means a cap on each six-month adjustment after the first adjustment.
Lifetime Cap
The lifetime cap limits how much the rate can increase over the life of the loan. If your starting rate is 5.50% and your lifetime cap is 5 percentage points, the highest possible rate under that cap structure would be 10.50%.
Example of a 5/6 ARM Payment Change
Suppose you take out a $400,000 5/6 ARM with a 5.50% starting rate and a 2/1/5 cap structure. In this example, the rate can rise by up to 2 percentage points at the first adjustment, by up to 1 percentage point at later adjustments and by up to 5 percentage points over the life of the loan.
| Timing |
Example Rate |
What It Shows |
| Years 1-5 |
5.50% |
The rate is fixed during the initial period. |
| First Adjustment After Year 5 |
Up to 7.50% |
The initial cap can allow the first major payment change. |
| Next Six-Month Adjustment |
Up to 8.50% |
The periodic cap may allow another increase sooner than an annual ARM would. |
| Lifetime Ceiling |
10.50% |
The lifetime cap limits the total increase to 5 percentage points above the starting rate. |
This example shows how the cap structure can shape payment risk if rates rise after the fixed period. Your actual payment depends on your loan terms, remaining balance, remaining term, index, margin and caps.
Why the Six-Month Adjustment Schedule Matters
The six-month adjustment schedule is what makes a 5/6 ARM different from a 5/1 ARM. After the fixed period, the loan may have more opportunities to reset.
- Payment changes can happen sooner. After the first adjustment, the next adjustment may come about 6 months later.
- Market changes can show up faster. If the index rises, the rate may have more frequent opportunities to move upward.
- Budget planning can be harder. You may need to prepare for payment reviews twice per year.
- Caps become especially important. The initial cap, periodic cap and lifetime cap determine how much movement is allowed.
A 5/6 ARM is not automatically riskier than every 5/1 ARM because pricing and caps vary by loan. But if two loans have similar rates and costs, the six-month adjustment schedule deserves close review.
When a 5/6 ARM Might Make Sense
A 5/6 ARM may make sense if you want a 5-year fixed period and understand how the six-month adjustment schedule works.
- You expect to move before the first adjustment. The 5-year fixed period may cover your expected time in the home.
- You expect to refinance before year 6. This can reduce exposure to the adjustable period, but refinancing depends on future rates, home value, credit, income and lender requirements.
- You want to compare pricing against a 5/1 ARM. A 5/6 ARM may be worth considering if the rate or cost difference is meaningful.
- You can afford payment changes after year 5. The loan is less risky if your budget can handle higher payments.
- You understand the caps. The six-month schedule makes the cap structure especially important.
When a 5/6 ARM May Be Riskier
A 5/6 ARM may be riskier if you expect to keep the loan well beyond the 5-year fixed period and your budget would be strained by payment increases.
- You need long-term payment certainty. A fixed-rate mortgage may fit better if you want the principal and interest payment to stay the same.
- You are relying on refinancing before the first adjustment. Refinancing is not guaranteed.
- You are stretching your budget at the starting payment. Later increases may be difficult to manage.
- You have not reviewed the six-month adjustment rules. A 5/6 ARM can adjust more frequently than a 5/1 ARM after the fixed period.
- You have not checked the maximum payment. The payment at the lifetime cap may be more important than the starting payment.
How To Stress-Test a 5/6 ARM
Before choosing a 5/6 ARM, look beyond the starting payment. The starting payment only tells you what the loan may cost during the fixed period. The stress test shows what could happen after the loan begins adjusting.
| Number To Review |
Why It Matters |
| Starting Payment |
Shows your payment during the initial 5-year fixed period. |
| Payment After First Adjustment |
Shows what could happen when the initial cap first applies. |
| Payment After The Next Six-Month Adjustment |
Shows how quickly another adjustment could affect your budget. |
| Payment At Lifetime Cap |
Shows the highest possible principal and interest payment under the rate cap structure. |
| Refinance Or Sale Backup Plan |
Helps you plan for what happens if you keep the loan past year 5. |
What To Review Before Choosing a 5/6 ARM
Before choosing a 5/6 ARM, compare the full loan terms rather than only the starting rate.
- The starting interest rate
- The length of the fixed period
- The first adjustment date
- Whether adjustments happen every 6 months after year 5
- The index used after the fixed period
- The lender’s margin
- The initial adjustment cap
- The periodic adjustment cap
- The lifetime cap
- The highest possible payment
- Loan fees and closing costs
- Whether the loan has a prepayment penalty
The Bottom Line
A 5/6 ARM is an adjustable-rate mortgage with a fixed rate for the first 5 years and adjustments every 6 months after that in many cases. It can provide early payment stability, but the six-month adjustment schedule can make the loan more sensitive to rate changes after year 5.
Before choosing a 5/6 ARM, compare it with 5/1 ARM and fixed-rate options. Pay close attention to the index, margin, initial cap, periodic cap, lifetime cap and highest possible payment. The starting payment matters, but the payment after the fixed period may matter more if you keep the loan longer than planned.
Frequently Asked Questions
What Is a 5/6 ARM?
A 5/6 ARM is an adjustable-rate mortgage with a fixed interest rate for the first 5 years. After that, the rate can usually adjust every 6 months based on the loan’s index, margin and caps.
What Does 5/6 Mean in a Mortgage?
The “5” means the starting rate is fixed for 5 years. The “6” usually means the rate can adjust every 6 months after the fixed period ends.
How Is a 5/6 ARM Different From a 5/1 ARM?
A 5/6 ARM usually adjusts every 6 months after the 5-year fixed period. A 5/1 ARM usually adjusts once per year after the 5-year fixed period.
What Happens After 5 Years on a 5/6 ARM?
After 5 years, the interest rate can adjust based on the loan’s index plus margin, subject to caps. The rate may then adjust again every 6 months, depending on the loan terms.
Is a 5/6 ARM a 30-Year Mortgage?
Many 5/6 ARMs have a 30-year repayment term, but the interest rate is fixed only for the first 5 years. After that, the rate can adjust according to the loan terms.
Can a 5/6 ARM Payment Go Up?
Yes. A 5/6 ARM payment can increase after the fixed period if the adjusted interest rate rises. Rate caps limit how much the rate can change, but they do not prevent increases.
Can a 5/6 ARM Payment Go Down?
Yes. A 5/6 ARM payment can go down if the adjusted rate decreases, depending on the index, margin, caps and any rate floor in the loan terms.
What Is a 2/1/5 Cap on a 5/6 ARM?
A 2/1/5 cap means the rate can change by up to 2 percentage points at the first adjustment, up to 1 percentage point at later adjustments and up to 5 percentage points over the life of the loan. For a 5/6 ARM, later adjustments may happen every 6 months.
Who Should Consider a 5/6 ARM?
A 5/6 ARM may be worth considering if you want a 5-year fixed period, understand the six-month adjustment schedule and can afford the payment if rates rise after the fixed period.
What Should I Compare Before Choosing a 5/6 ARM?
Compare the starting rate, fixed period, first adjustment date, six-month adjustment schedule, index, margin, initial cap, periodic cap, lifetime cap, loan fees and highest possible payment.
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