Cash you will not need for three years sits in an awkward middle ground. It is too long for a pure high-yield savings balance that you might spend next month, and too short for a multi-decade bond ladder meant to fund retirement. Bank certificates of deposit (CDs) and U.S. Treasury bills/notes both solve that middle: you lock a yield, accept some liquidity friction, and get paid to wait. Choosing between a CD ladder and a Treasury ladder—or splitting between them—comes down to early-withdrawal costs, auction timing, state tax treatment, and how obsessively you want to manage rollovers.
A ladder staggers maturities so cash frees on a schedule. A simple three-year ladder might hold equal slices maturing every six or twelve months. As each rung matures, you either spend the cash or reinvest at the long end of the ladder. The design reduces reinvestment-rate risk versus putting everything into one three-year instrument, and it restores partial liquidity without breaking the whole position.
Early-withdrawal penalties vs market exits
Bank CDs usually punish early exit with a fixed penalty: often several months of interest on short CDs, and more on multi-year CDs. The principal is generally safe at FDIC-insured banks up to coverage limits, but the penalty can erase months of yield if you break the CD in year one. Brokered CDs bought on the secondary market behave differently: you may sell before maturity at a market price that can be above or below par when rates move, and you may pay a spread. That is closer to bond-market risk than to a teller-window penalty.
Treasuries held to maturity repay par (plus final coupon/interest). If you need cash early, you sell in a deep market. Price can dip when yields rise, but for short-duration T-bills the mark-to-market swing is usually modest compared with long bonds. There is no bank-style “six months of interest” fee—only market price and any brokerage transaction cost. For emergency optionality inside a three-year plan, that flexibility often favors Treasuries over retail bank CDs with harsh break fees.
Auction timing and operational friction
Treasury ladders run on the auction calendar. T-bills are auctioned weekly; two- and three-year notes follow a regular schedule. Buying at auction through TreasuryDirect or a brokerage keeps you near the clearing yield without paying a secondary-market premium. The operational cost is attention: you must roll maturing bills, reinvest coupons if you hold notes, and keep settlement cash ready. Brokerage interfaces have made this easier, but a neglected Treasury ladder can leave cash sitting in a low-yield sweep for weeks.
Bank CD ladders are operationally simpler for many households. You open a handful of CDs at one or two banks, set calendar reminders, and roll each maturity into a new term. Relationship banks sometimes bump rates for existing customers. The trade-off is rate shopping: the best CD rates rotate among online banks, and sticking with one brand for convenience can leave dozens of basis points on the table.
State tax treatment—the quiet edge for Treasuries
Interest on U.S. Treasuries is exempt from state and local income tax in most states. Bank CD interest is fully taxable at federal and state levels. If you live in a high-tax state, that exemption can make a slightly lower Treasury yield beat a headline CD APY after tax. Run the comparison with your marginal state rate: after-tax CD yield ≈ APY × (1 − federal − state + interaction adjustments), while Treasury interest skips the state piece. For residents of states with no income tax, the edge disappears and pure APY plus liquidity rules dominate.
Also watch AMT and NIIT interactions only if you are already in complex tax situations; for most cash investors the state exemption is the main structural difference.
A simple split rule for three-year cash
Use this practical rule when the cash is truly earmarked for a horizon of roughly three years (home down payment in 2028, tuition, business reserve you hope not to touch):
- Core liquidity sleeve (about one-third): short T-bills rolling every four to thirteen weeks, or a no-penalty CD / HYSA, so an unexpected expense does not force a penalty or a bad sale.
- Yield sleeve (about two-thirds): laddered 12-, 24-, and 36-month instruments. Prefer Treasuries if your state tax rate is material or you value clean early exit; prefer top-tier FDIC CDs if the after-tax CD yield clearly wins and you accept break penalties.
- Never ladder money you might need inside six months into penalty CDs. That is how “emergency funds” become expensive mistakes.
Revisit the split when the yield curve changes shape. When the curve is inverted, short bills can out-yield three-year CDs—favor a bill-heavy ladder. When the curve steepens and term premiums return, extending a portion into two- and three-year rungs locks income you might not get by forever rolling four-week bills.
Implementation checklist
Title accounts correctly (individual, joint, trust) before you build size. Stay within FDIC limits per ownership category at each bank if you use CDs; Treasuries carry sovereign credit risk that most cash investors treat as near risk-free for planning purposes. Record purchase yields, maturity dates, and rollover instructions in one spreadsheet. Automate what you can: brokerage auto-roll for bills, bank maturity alerts for CDs.
Neither ladder is universally best. CDs win when a bank’s after-tax APY dominates and you will hold to maturity. Treasuries win when state taxes matter, when you want secondary-market exit without a contractual penalty, and when you are willing to respect the auction calendar. Split by purpose, not by slogan—and rebuild the ladder whenever a rung matures instead of letting cash idle in a default sweep.
