How Interest Rates Really Work: Why the Fed Doesn't Set Your Mortgage Rate

Start with the Fed

The Federal Reserve is the central bank of the United States. One of its main tools is a target for something called the federal funds rate.

The federal funds rate is what banks charge each other for overnight loans. You'll never borrow at that rate. But it's the foundation that many short-term rates are built on.

On September 16, 2026, the Fed raised its target range by a quarter point, to 3.75% to 4%. It was the first increase since 2023.

Why does the Fed move this rate? Its job, set by Congress, is to aim for stable prices and maximum employment. When inflation runs too hot, the Fed raises rates to make borrowing more expensive and cool spending down. When the economy weakens, it lowers rates to make borrowing cheaper and encourage spending.

In plain terms: the Fed sets the price of overnight money for banks. Everything else starts from there, but it doesn't all end there.

The prime rate: where the Fed reaches your wallet fastest

Banks use something called the prime rate as a base for many consumer loans. By long-standing convention, major banks set their prime rate at 3 percentage points above the top of the Fed's target range. So when the Fed moves, the prime rate usually moves the same day by the same amount.

A lot of variable-rate borrowing is tied to prime, plus an extra amount called a margin:

• Credit cards. Most have variable rates tied to prime.
• Home equity lines of credit (HELOCs). Usually prime plus a margin.
• Some personal loans and business lines of credit.

That's why credit card rates tend to change within a billing cycle or two of a Fed decision. The link is direct.

Why credit card rates are so high

If the Fed's rate is around 4%, why are credit cards around 22%?

Because the margin card companies add on top of prime is large. In the second quarter of 2026, the average rate on credit card accounts that charged interest was 22.15%. New card offers averaged about 23.79%.

That margin reflects a few things. Credit card debt is unsecured, meaning there's no house or car the lender can take back if you don't pay. Some borrowers do default. And cards come with rewards, fraud protection, and other costs the issuer covers.

The practical takeaway: when the Fed moves by a quarter point, your card rate moves by about a quarter point. But the Fed isn't why your card rate is high. The margin is.

The Treasury curve: the rates the market sets

Now we get to the rates the Fed doesn't directly control.

The U.S. government borrows money by selling Treasury securities, from short-term bills lasting weeks or months to 30-year bonds. The interest rates on those securities, called yields, are set by investors buying and selling them every day.

Here's a snapshot of the Treasury yield curve as of September 23, 2026:

Short-term Treasury yields tend to stay close to where the Fed has set its rate, and where investors expect it to go over the next year or two. Long-term yields depend much more on what investors expect over many years.

What moves long-term rates

Long-term yields, like the 10-year Treasury, respond to a mix of forces:

• Inflation expectations. If investors expect higher inflation over the next decade, they demand higher yields to make up for money losing value.
• Economic growth. A strong economy tends to push long-term rates up.
• Government borrowing. When the government needs to borrow more, and buyers are choosier, yields tend to rise.
• Auction demand. Weak demand at a Treasury auction can push yields up quickly. That happened in September 2026, when a weak five-year note auction helped send yields higher.
• Global factors. Investors around the world buy Treasuries. What happens in other bond markets and economies can spill over.
• Expectations about the Fed. Investors try to guess where the Fed is heading, not just where it is.

This is why the 10-year yield can rise even when the Fed is holding steady, and fall even when the Fed is raising rates. The Fed influences it. It doesn't control it.

Your mortgage rate follows the 10-year

This is the part that surprises the most people.

The 30-year fixed mortgage rate tracks the 10-year Treasury yield much more closely than it tracks the Fed. Lenders price mortgages off long-term borrowing costs, and then add a spread for their own costs, risk, and profit.

In late September 2026, the 10-year Treasury was about 5.12%, and the average 30-year fixed mortgage was 7.03%, according to Freddie Mac. That's a gap of roughly 1.9 percentage points.

So when you hear "the Fed raised rates, so mortgage rates will go up," that's only partly true. Mortgage rates went up this fall mainly because the 10-year Treasury climbed on inflation worries and heavy government borrowing. And if the Fed stopped raising rates tomorrow, mortgage rates could still stay high if the 10-year stays high.

Adjustable-rate mortgages are different. After their initial fixed period, their rates reset based on a short-term benchmark plus a margin, so they're more directly affected by where short-term rates are.

Other rates in your life

Auto loans

New car loans are influenced by a mix of short- and medium-term rates, the lender's funding costs, and your credit. When rates rise across the board, auto loans tend to get more expensive. Existing fixed-rate car loans don't change.

Federal student loans

Existing federal student loans have fixed rates. Rates on new federal student loans are set once a year using a formula tied to a 10-year Treasury auction. So a Fed decision doesn't change your existing federal loan.

Savings accounts and money market funds

This is where rising rates can work for you. High-yield savings accounts and money market funds tend to adjust their rates as short-term rates move. In early September 2026, some of the top high-yield savings accounts were paying a little over 4%.

Traditional savings accounts at many big banks often pay far less, sometimes close to nothing, even when short-term rates are high. Banks aren't required to pass higher rates along. That's why it's worth knowing what yours pays.

CDs

Certificates of deposit lock in a rate for a set term. New CDs tend to reflect current short- and medium-term rates. Once you open one, your rate stays fixed until it matures.

Bonds and bond funds

When interest rates rise, the prices of existing bonds fall. That's because new bonds pay more, so older bonds paying less become less valuable. The longer a bond's maturity, the more its price moves when rates change.

That's why many bond funds lost value as yields climbed this year. The other side is that new money going into bonds now earns higher yields than it has in a long time.

Real rates: the number that actually matters

There's one more concept worth understanding, and it changes how you look at every rate above.

The interest rate you see is the nominal rate. What matters for your buying power is the real rate: the nominal rate minus inflation.

In August 2026, inflation was running at 3.4% over the past year. So:

• A savings account paying 4% has a real return of roughly 0.6%. Your money is growing a little faster than prices.
• A savings account paying 0.5% has a real return of about negative 2.9%. Your money is losing buying power every year.
• A credit card charging 22% has a real cost of roughly 18.6%. Inflation doesn't make that debt much cheaper.

In plain terms: if your money earns less than inflation, it's shrinking, even if the balance goes up.

Your credit score changes your rate

Everything so far describes the general level of rates. The rate you personally get also depends on you.

Lenders set your rate based on how risky they think lending to you is. Your credit score, your income, your existing debt, and your down payment all matter. Two people applying for the same mortgage on the same day can get meaningfully different rates.

That's one of the few parts of the interest rate picture you actually control. Paying on time, keeping credit card balances low compared to your limits, and not opening a lot of new accounts at once can all help.

The shapes of the yield curve

The yield curve, the line connecting Treasury yields from short to long, can take a few different shapes. Each one tells you something about what investors expect.

Normal (upward-sloping). Longer-term rates are higher than shorter-term rates. That's the typical shape, because lenders usually want more compensation for tying up money longer. The curve in late September 2026 had this shape.

Inverted. Short-term rates are higher than long-term rates. That tends to happen when the Fed has raised short-term rates a lot and investors expect rates, and possibly the economy, to weaken later. Inverted curves have often come before recessions, though not every inversion has been followed by one.

Flat. Short- and long-term rates are close together. That often shows up during transitions, when investors aren't sure which way things are heading.

For households, the shape matters in practical ways. When the curve is inverted, short-term savings and CDs can pay as much as or more than longer-term options. When it's upward-sloping, locking money up for longer usually pays more.

A quick look back

It helps to remember how much rates have moved over the decades.

In the early 1980s, to fight double-digit inflation, the Fed pushed rates to levels that seem unthinkable now. The prime rate topped 20% at its peak, and mortgage rates went well into the teens.

From the 2008 financial crisis through much of the 2010s, rates were extremely low. The Fed held its rate near zero for years, and it did so again in 2020 during the pandemic. Mortgage rates briefly fell below 3%, and savings accounts paid almost nothing.

Then inflation surged coming out of the pandemic. Starting in 2022, the Fed raised rates quickly, reaching a range of 5.25% to 5.5% by July 2023. It cut in 2024 and 2025, held steady through the first part of 2026, and then raised again in September 2026.

The point isn't to predict where rates go next. It's that the super-low rates of the 2010s weren't normal, and today's rates aren't unusual by longer historical standards. Plans built on the assumption that money will always be nearly free, or always be expensive, tend to get caught off guard.

Putting it together

Here's the whole system in one view:

• The Fed sets the target for overnight bank lending.
• The prime rate moves with the Fed and drives most credit cards and HELOCs.
• Short-term Treasuries, savings accounts, and money market funds tend to follow where the Fed is and where it's expected to go.
• The 10-year Treasury is set by investors based on long-term expectations for inflation, growth, and government borrowing.
• Fixed mortgage rates follow the 10-year, plus a spread.
• Your personal rate depends on your credit and financial situation.
• Inflation decides whether any of it is actually helping or hurting your buying power.

What this means at different stages of life

If you're early in your career

Rising rates make borrowing more expensive, especially credit cards and car loans. They also make saving more rewarding. Building an emergency fund in a high-yield account, paying cards in full, and protecting your credit score matter more when rates are high.

If you're buying a home

Watch the 10-year Treasury, not just the Fed. Shop multiple lenders, since rates and fees vary. And plan around a payment you can afford at today's rate, rather than counting on refinancing later.

If you're getting close to retirement

Interest rates affect you in a few ways at once. Higher rates mean safer places to hold cash and short-term money pay more. They can also mean bond funds swing more in the short run. And if you're thinking about how to take money from DROP or other savings, what that money can earn in different places matters.

If you're retired

Higher rates can be good news for retirees who rely on interest income, since CDs, Treasuries, and money market funds pay more. They can also affect bond fund values and the cost of any borrowing. And for FRS Pension Plan retirees, your pension benefit itself isn't affected by interest rates at all, which is a real source of stability.

What I'm not going to do

I'm not going to tell you where rates are headed. The Fed doesn't know that for certain, and neither does anyone else. Forecasts change with every inflation report.

What I will say is this. When it comes down to it, you don't need to predict interest rates to make good decisions about them. You need to understand which rates affect you, what drives them, and how exposed you are when they move.

Let's look at how rates affect your plan

Interest rates touch almost every part of a financial plan: your debt, your savings, your home, your bonds, and the money you'll live on in retirement. Most people have never looked at all of those pieces together.

That's what I do. I'll walk through where your money sits today, which parts are exposed to rising or falling rates, and whether your cash, your bonds, and your borrowing are set up the way you'd want them to be. If you're a public employee, we'll also look at how your pension, DROP, and 457 fit into the picture.

I work as a fiduciary, which means I'm required to act in your best interest.

You don't need to know where rates are going. You need a plan that works either way.

Frequently asked questions

Does the Fed set mortgage rates?

No. The Fed sets a target for the overnight federal funds rate. Fixed mortgage rates follow the 10-year Treasury yield more closely, which is set by investors based on expectations for inflation, growth, and government borrowing.

What is the prime rate?

The prime rate is a benchmark banks use for many consumer loans. By convention, major banks set it 3 percentage points above the top of the Fed's target range, so it moves when the Fed moves. Credit cards and HELOCs are commonly tied to it.

Why are credit card interest rates so high?

Card rates are typically the prime rate plus a large margin, reflecting unsecured lending risk, defaults, and the cost of card features. The average rate on cards that charged interest was 22.15% in the second quarter of 2026.

Why do mortgage rates go up when the Fed isn't raising rates?

Because mortgage rates follow the 10-year Treasury yield, which can rise on inflation expectations, strong growth, heavy government borrowing, or weak demand at Treasury auctions, even when the Fed holds steady.

What is a real interest rate?

A real interest rate is the nominal rate minus inflation. It shows whether your money is actually gaining or losing buying power.

How do rising interest rates affect bonds?

When rates rise, prices of existing bonds generally fall, with longer-term bonds affected more. New bonds, however, pay higher yields.

Educational content only. Not individualized investment, tax, or legal advice. Rates cited are as of September 2026 and change frequently. Past performance does not guarantee future results. Benowitz Wealth Management is a brand of Joy Financial Group LLC, a Florida state-registered investment adviser.

Neither Joy Financial Group LLC nor Benowitz Wealth Management is affiliated with, endorsed by, or employed by the Florida Retirement System, the Florida Division of Retirement, the State Board of Administration of Florida, MyFRS, or any government agency. FRS members may obtain free, unbiased guidance from the MyFRS Financial Guidance Line at 1-866-446-9377.