I built my first CD ladder with five rungs spaced exactly one year apart, because that is the shape every example online shows. Sixteen months in, a $4,200 car repair arrived three months before my next maturity. The ladder had done its job earning interest. It had not done its job being there when I needed it, and breaking a 3-year rung cost me several months of interest in penalties. That repair taught me the real question is not how many rungs your ladder has. It is which rung spacing is better for money you might actually spend.
What 6-month spacing gets you
With rungs maturing every six months, you get a penalty-free decision point twice a year. The classic shape is four rungs: 6, 12, 18, and 24 months. Each time a rung matures, you roll it into a fresh 2-year CD, and after 18 months the whole ladder earns 2-year rates with a quarter of it coming due every six months. If cash comes up between maturities, you break one rung and pay the penalty on that rung only, not the whole balance.
The price is yield, and it is smaller than most people assume. Shorter terms usually pay less, so a ladder weighted toward short rungs earns a bit less than one built on 1- to 5-year terms. On a $20,000 ladder the gap is often tens of dollars a year, not hundreds. That is why I stopped treating this as a yield question. The spacing question is a flexibility question, and the yield difference is the fee you pay for the answer you want.
What 12-month spacing gets you
The one-year-apart ladder is the default for a reason. Five rungs of 1, 2, 3, 4, and 5 years keep most of your money in longer terms, which is where the higher rates live. You get one decision a year, which is honestly about as much attention as most savings deserve. Fewer rungs also means fewer accounts to open and fewer grace periods to watch.
Where the annual ladder quietly wins is discipline cost. Every maturity is a moment you have to act. Banks typically auto-renew a maturing CD into the same term at the current rate if you do nothing during the 7 to 10 day grace period. With 6-month spacing you face that moment twice a year, and each one you sleep through locks a rung into a fresh short term at whatever rate the bank feels like posting. Twice as many decisions is twice as many chances to miss one. I know this because I have missed one.
My decision rule
If the money might get spent more than once a year, use 6-month spacing. Emergency-adjacent savings, a down payment fund with a fuzzy closing date, anything where a surprise bill is a when not an if. If the money is genuinely long-term and you will leave it alone, use 12-month spacing and take the extra yield. Set-and-forget cash does not need twice-yearly access points; it needs to sit still and earn.
Two constraints override the preference. First, minimum deposits. Banks commonly ask $500 to $2,500 per CD, so a $5,000 ladder can only hold two or three rungs at some banks, and 6-month spacing is off the table entirely at that size. Second, the rate gap. Before you build anything, compare the best short-term CD rate against the best longer-term rate and your savings account. If the longer terms barely beat savings, a ladder of any spacing is theater, and the highest-rate single option wins. Check the gap on your numbers before you commit to a structure.
One more option most writeups skip: uneven spacing. Nothing says the rungs have to be evenly spaced. The setup I run now puts short rungs up front and long rungs in back: 6 and 12 months for liquidity, then 3, 4, and 5 years for yield. The front of the ladder handles surprises. The back of the ladder earns. You get the twice-yearly decision point where it matters and the annual rhythm where it does not, and a missed grace period on a back rung only costs you the long-term rate you wanted anyway.
The honest failure mode is the same in every shape: a ladder you do not tend. Set a calendar reminder for every maturity date when you open the rungs. The grace period is short, the auto-renewal is silent, and no spacing choice survives inattention.
Frequently asked questions
What is rung spacing in a CD ladder?
Rung spacing is the time between maturity dates in your ladder. Twelve-month spacing means one CD matures each year; six-month spacing means one matures every half year. The spacing sets how often you get a penalty-free decision point.
Does 6-month spacing earn less than 12-month spacing?
Usually, a little. Tighter spacing keeps more of your money in shorter-term CDs, which generally pay less. The yield gap is often small, tens of dollars a year on a $20,000 ladder, which is why the flexibility question matters more than the yield question.
Can you mix 6-month and 12-month rungs in one ladder?
Yes. A common setup puts shorter rungs near the front for liquidity and longer rungs at the back for yield, for example 6 and 12 months up front and 3, 4, and 5 years behind them.
What happens if you miss the grace period at maturity?
The bank typically auto-renews the CD into a new CD of the same term at its current rate. A missed grace period on a 6-month rung locks that money into another 6-month term. The grace period is usually 7 to 10 days.
How many rungs should a CD ladder have?
Three to five rungs covers most people. More rungs mean more frequent access but also more accounts to manage and more minimum deposits to fund. Banks commonly require $500 to $2,500 per CD, which limits how many rungs a small balance can hold.
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