You can buy U.S. Treasury bills at auction through TreasuryDirect or through a brokerage such as Fidelity, Charles Schwab, Vanguard Brokerage, or E*TRADE. Series I savings bonds are different: electronic I bonds are sold to individuals on TreasuryDirect, not as a standard brokerage ticker. Choosing the channel affects fees, auction workflow, and how easily you can sell before maturity.
Platform setup deep-dive: TreasuryDirect account basics. Product primers: T-bills for cash and Series I bonds basics. Everyday cash still often lives in CDs vs high-yield savings.
Side-by-side
| Need | TreasuryDirect | Brokerage (Fidelity, Schwab, Vanguard, E*TRADE, etc.) |
|---|---|---|
| Electronic I bonds / EE bonds | Yes (primary retail channel) | Generally no for new electronic I bonds |
| T-bills, notes, bonds, TIPS at auction | Noncompetitive bids; hold with Treasury | Auction and often secondary market |
| Sell marketable Treasuries before maturity | Awkward / limited vs a broker secondary desk | Usually straightforward secondary trades |
| Account fees for Treasuries | No broker commission (Treasury platform) | Many brokers charge $0 commission on Treasuries; watch spreads and settlement cash drag (Brokerage account fees) |
| Portfolio view with stocks/ETFs | Separate login from your broker | Single household view |
| Zero-interest C of I cash parking | Common inside TreasuryDirect | Broker sweep / SPAXX-style money market instead |
Fees and friction in practice
- TreasuryDirect: No brokerage ticket fee. Friction is operational—bank linking, auction schedules, and leaving cash in a Certificate of Indebtedness that pays 0% until you reinvest or redeem to your bank.
- Brokerage: Stated commissions on U.S. Treasuries are often $0 at major firms, but you still care about bid-ask spreads if you sell early, settlement timing, and whether idle cash sits in a low-yield sweep.
- I bonds: Annual purchase limits and the 12-month redemption lock apply on TreasuryDirect regardless of what your broker advertises for T-bills.
Worked example: $20,000 cash sleeve for 6 months
Priya has $20,000 she will not need for six months. Path A: open TreasuryDirect, noncompetitive bid on a 26-week T-bill, hold to maturity, schedule proceeds back to an Ally checking account. Path B: buy a 26-week bill at auction inside a Schwab brokerage account already used for index funds.
If Priya is sure she can hold to week 26, both paths can work; TreasuryDirect avoids another product inside the taxable brokerage lot list. If Priya might need $8,000 in week 8, the brokerage secondary market is usually simpler than trying to free marketable Treasuries from TreasuryDirect’s hold-to-maturity bias. Separately, Priya parks $5,000 in electronic I bonds on TreasuryDirect for inflation-aware surplus she can lock for a year—something Path B’s brokerage cannot replace with a true I bond.
For money that must move same day, a high-yield savings account still beats either Treasury channel.
Liquidity and auction mechanics
- Prefer noncompetitive bids when you want a stated face amount at the auction high rate/yield and will hold to maturity.
- Use a brokerage when you want optional early sale of marketable bills/notes.
- Keep emergency cash outside both vehicles if you need FDIC/NCUA same-day liquidity.
- Do not confuse T-bill ladders with I bond rules—the products share a Treasury brand, not the same liquidity.
Named institutions in this comparison include TreasuryDirect.gov (U.S. Department of the Treasury), Federal Reserve auction infrastructure, Fidelity, Charles Schwab, Vanguard Brokerage, E*TRADE from Morgan Stanley, Ally Bank, and Capital One 360 for the cash buffer beside Treasuries.
Checklist
- List whether you need I bonds (TreasuryDirect) or only marketable T-bills.
- Decide hold-to-maturity vs possible early sale.
- Compare 0% C of I drag vs broker sweep yield on idle cash.
- Confirm auction deadlines and bank-link timing before settlement week.
- Keep true emergency funds in savings/CDs you can reach quickly.
- Re-read I bond purchase caps and 12-month lock before you buy. Competitive vs noncompetitive auction bids and settlement: Treasury auction competitive bid basics.
Educational only. Not investment, tax, or personalized financial advice. Auction rules, fees, and product menus change; confirm on TreasuryDirect.gov and your brokerage disclosures.