Best Solo 401k Providers: Fidelity vs Vanguard vs E*TRADE

Opening a Solo 401k is not like opening a checking account. The features depend entirely on the “Plan Document” provided by the broker. Most investors flock to Fidelity because it is free, only to discover later that it does NOT support Roth contributions or Loans. Surprisingly, E*TRADE has emerged as the feature king among free brokers, offering both Roth and Loan options that others charge for. If you want a wealth-building Ferrari without the fees, you need to choose carefully. Here is the definitive comparison for 2026.

BMT Wall St Team BMT Wall St Team · 📅 Feb 2026 · ⏱️ 6 min read · INVESTING › PROVIDERS
Fidelity
Basic
No Roth / No LoansFact
E*TRADE
Winner
Roth + Loans SupportedGood
Vanguard
Fees
Now $20/Fund (Ascensus)Warn
Comparison of Fidelity, E*TRADE, and Vanguard Solo 401k application forms highlighting Roth options

The forms tell the story: E*TRADE explicitly offers the Roth option that others miss.

1. The “Free” Trap: What Are You Missing?

“Free” usually means “stripped-down.” But one broker is breaking the mold.

🏢 Fidelity (Standard)
  • Cost: $0 Setup
  • Roth: ❌ NO (Pre-Tax Only)
  • Loans: ❌ NO
💎 E*TRADE (Standard)
  • Cost: $0 Setup
  • Roth: ✅ YES (Fully Supported)
  • Loans: ✅ YES (Rare for Free Plans)

2. Fidelity vs Vanguard vs E*TRADE (Checklist)

Here is the side-by-side truth. E*TRADE is the surprising winner for features.

Feature Fidelity E*TRADE Vanguard
Setup Fee $0 $0 $20/fund (waived usually)
Roth Option NO (Standard Plan) YES YES (Roth 401k)
401k Loans? NO YES (Up to $50k) NO
Verdict Good for Pre-Tax only Best Overall Fees increased

*Note: Vanguard recently sold its Solo 401k business administration to Ascensus, adding fees and complexity. We currently recommend E*TRADE for new accounts due to the loan feature.

3. Strategy: When to Pay for a Plan

Even E*TRADE has limits.

  • Scenario A: You want to buy Real Estate. Standard brokers (even E*TRADE) only let you buy stocks and bonds. If you want to use your 401k to buy a rental property, you MUST pay for a Custom Plan Provider (e.g., MySolo401k, Nabers).
  • Scenario B: Mega Backdoor Roth. While some brokers allow basic Roth, the massive “Mega Backdoor” strategy (contributing up to $69k+ in after-tax dollars) usually requires a custom plan document.
  • How it works: You pay the provider ~$500 for the legal documents. You then take those documents to a bank to open the account.

4. Warning: The Administrator Burden

With great power comes great paperwork.

Plan Assets (Form 5500-EZ Trigger) Current: $250k / Trigger: $250k
⚠️ Warning: Over $250k Assets
You are the Admin
Unlike a workplace 401k, YOU are responsible for filing IRS Form 5500-EZ once your plan assets exceed $250,000. Fidelity/E*TRADE will NOT do this for you. They only send you statements. Missing this filing carries massive penalties.

5. Frequently Asked Questions

Can I switch from Fidelity to E*TRADE?
Yes. This is called a “Rollover” or “Restatement.” You can move your assets to E*TRADE to gain access to the Loan feature. Ensure you follow the direct rollover rules to avoid taxes.
Is the loan really tax-free?
Yes. You borrow your own money. The interest you pay (Prime + 1-2%) goes back into your own 401k account, not to the bank. It is the cheapest loan you will ever get.