VUSXX vs HYSA: Vanguard Treasury Fund or Savings Account in 2026?

Vanguard's Treasury Money Market Fund (VUSXX) is one of the largest and cheapest ways to hold short-term Treasury exposure, and it raises the same question as its ETF cousin SGOV: does a Treasury fund actually beat a high-yield savings account once state income tax is factored in? The mechanics are the same. Treasury interest is exempt from state and local income tax under 31 U.S.C. § 3124, while savings-account interest is taxed like ordinary wages. VUSXX passes most of that exemption through, because it invests primarily in Treasury bills, notes, and Treasury-collateralized repurchase agreements.

Where VUSXX actually differs from SGOV, and from a HYSA, is access. Vanguard requires a $3,000 initial investment to open VUSXX, there's no equivalent minimum for a savings account, and settlement takes a day or two longer than moving cash within a bank. This guide walks through the after-tax math, the minimum-investment hurdle, and how VUSXX stacks up against both a HYSA and its own ETF sibling.

Quick answer

If you already have $3,000 sitting at Vanguard and pay a meaningful state income tax rate, VUSXX is usually the better after-tax home for cash you don't need same-day. Its 0.09% expense ratio and Treasury-heavy holdings put its tax treatment on par with SGOV, comfortably ahead of a taxable HYSA once you clear roughly a 5% marginal state rate. If you don't have $3,000, live in a no-income-tax state, or want zero brokerage friction, a top-of-market HYSA or SGOV are the simpler doors to open.

VUSXX vs HYSA: Side-by-Side Comparison

VUSXX vs SGOV: The Real Difference Isn't Tax Treatment

Readers comparing VUSXX to a HYSA usually already know about SGOV, and it's worth being direct: VUSXX and SGOV do nearly the same job. Both hold short-term Treasury exposure, both charge a 0.09% expense ratio, and both have historically reported a high enough percentage of income from direct U.S. government obligations to clear the roughly 50% threshold that California, New York, and Connecticut require before any state exemption applies. If tax treatment were the only variable, they'd be interchangeable.

The variable that actually separates them is access. SGOV is an ETF: it trades on any brokerage, all day, with no minimum beyond one share (roughly $100). VUSXX is a Vanguard mutual fund with a $3,000 initial minimum, priced once per day, and it works best inside a Vanguard account. If you're already a Vanguard customer with $3,000 or more sitting in cash, VUSXX is a clean, direct choice. If you bank at Fidelity, Schwab, or elsewhere, or you're starting with less than $3,000, SGOV reaches the same tax outcome without the minimum or the single-broker friction. See our SGOV vs HYSA guide for the full after-tax math, which applies here as well.

How the State-Tax Math Works

The formula is the same one that applies to any Treasury-heavy fund: divide the fund's yield by (1 minus your marginal state tax rate) to get its tax-equivalent yield, then compare that number to the best HYSA APY you can open.

Consider a Vanguard customer in California's 9.3% marginal bracket holding $50,000. If VUSXX yields roughly the same as SGOV (both track short-term Treasury rates closely), the tax-equivalent yield calculation works out the same way: a nominal Treasury-fund yield in the mid-3% range becomes equivalent to a fully taxable rate near 3.9-4.0% after grossing up for the exemption. Only the very top of the HYSA market clears that bar. In a no-income-tax state like Texas or Florida, the exemption is worth nothing, and the higher pre-tax rate simply wins.

Figures are illustrative estimates based on a Treasury-fund yield near SGOV's; VUSXX's actual current yield and government-obligation percentage should be verified on Vanguard's fund page before acting.

The $3,000 Minimum Is the Real Gatekeeper

For anyone with less than $3,000 to invest, VUSXX simply isn't available yet. That rules it out for a starter emergency fund or a first-time saver, groups for whom a $0-minimum HYSA is the only realistic option regardless of tax treatment. Vanguard's minimum typically applies to the initial purchase only; balances can usually dip below $3,000 afterward without forcing a sale, but confirm current policy on Vanguard's site since fund rules can change.

This minimum is also why VUSXX tends to suit larger, more established cash positions better than SGOV does. A saver opening their first brokerage account with $1,200 has no path into VUSXX today; the same saver can buy roughly 12 shares of SGOV instead.

Where VUSXX Wins (Pros)

• After-tax yield in high-tax states, on par with SGOV, once you clear the $3,000 minimum.
• No $250,000 cap, since Treasury obligations carry the full faith and credit of the U.S. government rather than a per-bank FDIC limit.
• Very low expense ratio (0.09%), among the cheapest Treasury funds on the market.
• Automatic reinvestment and easy integration if you already manage other holdings at Vanguard.

Where VUSXX Falls Short (Cons)

• $3,000 minimum initial investment, a real barrier that SGOV and most HYSAs don't have.
• Slower access, two to three business days to spendable cash versus same-day at many banks.
• Best held at Vanguard, since buying it elsewhere often adds transaction costs.
• Worthless tax edge in no-income-tax states, where a top HYSA likely pays more outright.

How to Decide

Choose a high-yield savings account if you're starting with less than $3,000, live in a no-income-tax state, or want same-day access with no brokerage account involved.

Choose VUSXX if you're already a Vanguard customer, can clear the $3,000 minimum, and pay a state income tax rate of roughly 5% or higher, where the exemption usually flips the after-tax ranking in its favor.

Choose SGOV instead of VUSXX if you want the same tax treatment without the minimum or the single-broker constraint.

Use a hybrid if you have $3,000-plus in a high-tax state: keep one month of expenses in a HYSA for instant access, and move the rest into VUSXX for the after-tax edge. For help sizing that split, see our emergency fund guide.

Sources

• Vanguard Treasury Money Market Fund (VUSXX) fund page
• 31 U.S.C. § 3124
• FDIC: understanding deposit insurance

Yields and government-obligation percentages change; verify current figures on Vanguard's site before acting.

Methodology

SwitchWize compares money market fund structure, fees, and minimums against issuer fund pages and cross-references savings APYs against institution disclosures, verified weekly. After-tax comparisons use published state marginal rates. Rankings are never influenced by advertiser compensation. For full details, see our methodology.

This is educational information, not personalized financial advice.