Comparisons · 3 Oct 2026 · 8 min read

High-yield savings vs CDs vs Treasury bills: where should your cash go?

Short answer: for money you may need soon, a high-yield savings account is the simplest choice because the rate is competitive and you can withdraw any time. If you will not need the money for a fixed period, a CD or a Treasury bill can lock in today's rate. Treasury interest is exempt from state and local income tax, which helps in high-tax states. All of these are low-risk, but they are not identical: they differ in access, rate certainty, tax treatment and how the safety works.

How do the main safe-cash options compare?

	High-yield savings	Certificate of deposit	Treasury bill
Safety	FDIC or NCUA insured up to $250,000 per depositor, per bank, per ownership category	Same insurance	Backed by the US government
Access	Withdraw any time (a few banks limit transfers)	Locked for the term, early withdrawal costs a penalty	Hold to maturity, or sell on the market any day, at a price that may differ slightly
Rate	Variable, can change at any time	Fixed for the term	Fixed once bought, set at auction
Terms	None	Commonly 3 months to 5 years	4 weeks to 52 weeks
Tax	Federal, state and local income tax	Federal, state and local income tax	Federal income tax only, exempt from state and local
How to buy	Online bank or credit union	Bank, credit union or brokerage	TreasuryDirect or a brokerage

When does a high-yield savings account win?

Whenever you need flexibility. Emergency funds, near-term goals with an uncertain date, and "I might need this" money belong here. The yield floats with interest rates, so it will rise when rates rise and fall when rates fall, but you can always move the money if a better rate appears. Look for an account with no monthly fee, no minimum, and FDIC or NCUA insurance, and avoid being lured by a bonus rate that drops after a few months. See where your emergency fund should sit.

When does a CD make sense?

A CD is useful when you know you will not touch the money for a set time, and you want certainty. If you expect interest rates to fall, a longer CD locks in today's rate. If rates rise, you are stuck with the lower one. A common approach to handle that uncertainty is a CD ladder: split the money across CDs of staggered lengths, say 6, 12 and 18 months, so something matures regularly and you can reinvest at current rates. Be aware that early withdrawal typically costs several months of interest, which can wipe out the advantage, so only commit money you are sure you will not need.

When are Treasury bills better?

T-bills are sold at a discount and mature at face value, and the difference is your interest. They are backed by the government and the interest is exempt from state and local taxes. That exemption matters most if you live in a state with high income taxes: a slightly lower stated yield can leave you with more after tax. For example, if a T-bill yields 4.0% and your combined state and local rate is 8%, the equivalent taxable yield is about 4.35%. T-bills are also easy to ladder, because each maturity gives you cash back every few weeks or months.

What about I bonds and money market funds?

Series I savings bonds pay a rate that combines a fixed rate and an inflation adjustment, which helps protect purchasing power. You can buy up to $10,000 a year per person electronically, must hold them for at least 12 months, and lose the last three months of interest if you redeem within five years.
Money market funds at a brokerage invest in short-term securities and often pay competitive yields with same-day or next-day access, but unlike bank accounts they are not FDIC insured. They are considered low-risk, not no-risk.

A simple way to choose

Emergency fund: high-yield savings, for instant access.
Goal in 6 to 24 months with a fixed date (tuition, a down payment): CDs or T-bills matched to the date.
Extra cash you may or may not need: a ladder, or a money market fund.
Long-term money (5+ years): none of these. Safe cash tends to trail inflation over long periods, so long-term goals belong in diversified investments. See how inflation erodes savings.

For a sense of how a short-term goal compares across products, try Compare Lab. And to check how many months of expenses your cash covers, our emergency runway tool gives you the answer in minutes.

General education, not investment advice. Rates and rules change often, so check the current figures before you decide.

Frequently asked questions

Is a high-yield savings account safe?

Yes, as long as it is at an FDIC-insured bank or an NCUA-insured credit union. Deposits are insured up to $250,000 per depositor, per institution, per ownership category.

Are CDs better than high-yield savings accounts?

Not always. A CD locks in a fixed rate for a set term, which helps if rates fall, but early withdrawal costs a penalty and you cannot benefit if rates rise. A high-yield savings account gives you full access and a variable rate.

Are Treasury bills safer than bank accounts?

Both are considered very safe. Treasury bills are backed by the full faith and credit of the US government, and bank deposits are insured up to $250,000. The practical differences are tax treatment, access and how you buy them.

Is Treasury bill interest taxed?

It is subject to federal income tax but exempt from state and local income tax, which makes T-bills more attractive in high-tax states.

Where should I keep my emergency fund?

In a liquid, insured account such as a high-yield savings account, so you can access the money immediately without a penalty or market risk.