FDRXX vs SPAXX: Which Is Better? Yield, Taxes & Safety Compared
POINTS
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SPAXX Is Convenient: It can serve as a Fidelity core position for uninvested cash.
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FDRXX Is Purchased Separately: It is generally bought as a money market fund rather than used as the core position.
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Yields Can Differ: Compare the latest 7 day yields before choosing either fund.
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Both Are Government Money Market Funds: Both focus on liquidity, stability, and income.
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State Tax Benefits Can Differ: The amount eligible for state tax exemption can vary by fund and tax year.
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You Can Generally Switch: Eligible Fidelity accounts can generally move money from SPAXX to FDRXX.
Fidelity’s Government Cash Reserves (FDRXX) and Government Money Market Fund (SPAXX) are short‐term government funds.
Both aim to preserve capital while generating income.
- SPAXX is available in all Fidelity accounts, whereas
- FDRXX is generally limited to retirement accounts.
Which Fidelity Core Position Should You Choose?
Compare SPAXX, FZFXX, FCASH, and the FDIC sweep to understand yields, taxes, insurance, and cash access.
Yields Comparison
FDRXX and SPAXX are both Fidelity government money market funds, but their current yields are slightly different.
(Note: yields are annualized and approximate. Exact rates change daily.) Both funds maintain a stable $1 NAV. Past performance is not indicative of future results.
When Does SPAXX Pay Interest? See the Exact Payment Schedule
Which Is Safer: FDRXX vs. SPAXX
| Feature | FDRXX (Government Cash Reserves) | SPAXX (Government Money Market Fund) |
|---|---|---|
| Type | Government money market fund | Government money market fund |
| Inception | May 10, 1979 | February 5, 1990 |
| Assets | About $245.2 billion | About $461.3 billion |
| Net expense ratio | 0.35% | 0.42% |
| Minimum portfolio requirement | Normally at least 99.5% in cash, U.S. government securities and fully collateralized repurchase agreements | Normally at least 99.5% in cash, U.S. government securities and fully collateralized repurchase agreements |
| Typical holdings | U.S. Treasury bills and coupons, agency securities and U.S. government repurchase agreements | U.S. Treasury bills and coupons, agency securities and U.S. government repurchase agreements |
| Weighted average maturity | Short-term money market portfolio | About 42 days as of September 8, 2026 |
| Credit quality | Government-focused portfolio with very short-term securities | Government-focused portfolio with very short-term securities |
| Daily liquidity | 58% as of September 9, 2026 | High liquidity maintained under money market fund rules |
| Weekly liquidity | 73% as of September 9, 2026 | High liquidity maintained under money market fund rules |
| NAV | $1.00 | $1.00 |
| NAV objective | Seeks to preserve a stable $1.00 share price | Seeks to preserve a stable $1.00 share price |
| Redemption fees | No fee upon sale of shares | No fee upon sale of shares |
| FDIC insurance | Not FDIC insured | Not FDIC insured |
| Government guarantee | Not guaranteed by the U.S. government | Not guaranteed by the U.S. government |
So, which Is Safer?
If you’re choosing between FDRXX and SPAXX primarily for safety, you’ll find that both have very similar risk profiles.
Both are government money market funds that primarily invest in U.S. government securities and government-related repurchase agreements, and both seek to maintain a stable $1.00 share price.
Neither is FDIC insured or guaranteed by the U.S. government, so you should not treat either fund as completely risk-free.
For you as an investor, you need to focus more on
- Funds’ expenses
- Yields
- Liquidity, and
- Portfolio composition rather than a meaningful difference in their underlying safety.
Is SPAXX or FCASH Better?
Compare SPAXX and FCASH on yield, liquidity, taxes, fees, protection, and how each option holds your Fidelity cash.
FDRXX vs. SPAXX: Federal & State Tax
Federal tax
Dividends from both funds are taxed as ordinary income.
Even though the income is from interest, the funds distribute it as interest dividends, so it appears on 1099-DIV and not on 1099-INT.
State tax
Most states exempt interest on U.S. government obligations.
Both SPAXX and FDRXX invest heavily in U.S. Treasuries, but also in agencies.
California, Connecticut, and New York impose stricter rules: they only exempt dividends if the fund meets a minimum % in U.S. obligations.
FDRXX vs. SPAXX: State Tax Treatment by State
Whether the U.S. government portion of FDRXX and SPAXX dividends can be subtracted from your state taxable income.
Hover or tap a state to see details
Which Accounts Can Use FDRXX or SPAXX?
| Account Type | SPAXX Available? | FDRXX Available? |
|---|---|---|
| Taxable brokerage | Yes | No (not offered) |
| Traditional/Roth/Rollover IRA | Yes | Yes (only IRA) |
| 401(k) / 403(b) (rollovers) | Yes (as IRA) | Yes (if held as IRA) |
| HSA | Yes | No |
| Custodial (UGMA/UTMA) | Yes | No |
| Trust (non-retirement) | Yes | No |
| 529 plans | Plan-dependent (usually own cash fund) | Not relevant |
(“Yes” means typically available as a core or direct fund. “No” means not a selectable option.)
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Learn How to Invest in AmazonCan You Switch From SPAXX to FDRXX?
Yes, you can switch from SPAXX to FDRXX in a Fidelity account when FDRXX is an eligible core position for that account.
- Log in to your Fidelity account.
- Open the account that currently uses SPAXX as its core position.
- Go to the Positions tab and select your current core position.
- Select Change Core Position if FDRXX is available for your account.
- Choose Fidelity Government Cash Reserves (FDRXX) from the available options.
- Review the change and select Submit to confirm it.
After the change, eligible uninvested cash will be held in FDRXX instead of SPAXX.
FDRXX vs. SPAXX: Pros and Cons
FDRXX
FDRXX Pros
- Lower expense ratio.
- Slightly higher current yield.
- Government money market fund with a stable $1.00 NAV objective.
- High liquidity.
- A portion of income may qualify for state-tax exemption, depending on your state and the fund’s annual government-securities percentage.
FDRXX Cons
- Not available as a core position in every Fidelity account.
- Less convenient for automatic cash sweeping in accounts where it is not a core option.
- Yield can change as short-term interest rates change.
SPAXX
SPAXX Pros
- Available as a core position in many Fidelity accounts.
- Convenient for automatically holding uninvested cash.
- Government money market fund with a stable $1.00 NAV objective.
- High liquidity.
- A portion of income may qualify for state-tax exemption, depending on your state and the fund’s annual government-securities percentage.
SPAXX Cons
- Higher expense ratio than FDRXX.
- Current yield may be slightly lower than FDRXX.
- Yield can change as short-term interest rates change.
SPAXX vs. FDRXX FAQ
SPAXX generally has a $2,500 minimum, or $500 for IRA accounts. FDRXX may have no separate minimum when used as an eligible core position.
No. Neither SPAXX nor FDRXX directly supports check-writing.
No. SPAXX and FDRXX are mutual funds, not bank accounts, so they are not FDIC-insured or bank-guaranteed.
A sweep option automatically places eligible uninvested cash into a designated cash position, such as a money market fund or bank sweep.
SPAXX and FDRXX are separate Fidelity government money market funds with different fund structures, expenses, and investment policies.
SPAXX and FDRXX have different expense ratios, and neither typically charges sales loads or redemption fees.
Distributions from SPAXX and FDRXX are generally reported on Form 1099-DIV as ordinary dividends. A portion attributable to U.S. government securities may qualify for state tax exemptions, depending on your state’s rules.
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