Solo 401(k) for Accountants & CPAs — 2026 Calculator

Self-employed CPAs, bookkeepers, and accounting consultants are among the best-positioned professionals to maximize Solo 401(k) contributions — they understand the tax math and can optimize every dollar.

2026 max contribution

$70,000

Typical income range

$70,000–$250,000

Catch-up (age 50+)

+$7,500

Deadline to open

Dec 31, 2026

Your situation

Takes under 2 minutes · We never store your inputs

✦ Import from document

Paste an offer letter, 1099, contract, or any document with income details — Claude will fill the fields for you.

Affects catch-up contribution limits (age 50+, 60–63 enhanced)

From Schedule C line 31, or your best estimate if mid-year

Enter 0 if you have no day job. Affects IRA deductibility and total 401(k) room.

An HDHP (high-deductible plan) unlocks HSA contributions — the only triple-tax-advantaged account

Traditional IRA, SEP-IRA, or SIMPLE IRA balances. Affects backdoor Roth eligibility.

We never store your inputs. All calculations happen on our server.

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Your 2026 retirement plan

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Solo 401(k) for Accountants & CPAs: What You Need to Know

Business structure

Solo accounting practices often operate as sole proprietors, single-member LLCs, or S-Corps. S-Corp election is particularly common above $100,000 in net income to reduce SE taxes on distributions.

Income pattern & timing

Tax season (January–April) generates the bulk of annual revenue. Front-load contributions in Q2 after the tax season cash flow arrives.

Key strategy

CPAs who advise clients on Solo 401(k) often underinvest in their own plans. The same strategies you recommend — employee deferrals + employer contributions + Roth options — apply to your own practice.

Solo 401(k) vs. SEP-IRA for accountants & cpas

A Solo 401(k) allows both an employee deferral (up to $23,500 in 2026) and an employer contribution (up to 25% of net compensation), for a combined maximum of $70,000. A SEP-IRA only allows employer contributions — no employee deferral. This means self-employed accountants & cpas earning under approximately $120,000 in net income can typically contribute more to a Solo 401(k) than a SEP-IRA.

How to open a Solo 401(k) as a accountant

  1. Get an EIN (free at IRS.gov, takes 5 minutes online). You need this even as a sole proprietor.
  2. Choose a provider. Fidelity, Schwab, and Vanguard offer free Solo 401(k) plans. Fidelity supports both traditional and Roth contributions with no fees.
  3. Open the account before December 31 of the tax year you want contributions to count.
  4. Fund the account by your tax filing deadline — April 15, or October 15 if you file an extension.

Frequently Asked Questions

Can accountants & cpas open a Solo 401(k)?

Yes. Self-employed accountants & cpas with Schedule C or 1099 income qualify for a Solo 401(k) as long as they have no full-time W-2 employees other than a spouse. The 2026 contribution limit is $70,000 ($77,500 with catch-up for those 50+).

Can a CPA who also works as an employee at a firm open a Solo 401(k) for side work?

Yes. 1099 consulting, bookkeeping clients, and tax preparation side work all qualify as self-employment income. The Solo 401(k) applies to that income independently of your firm employment.

Should a solo CPA practice use a SEP-IRA or Solo 401(k)?

For most solo CPAs with net income under $300,000, a Solo 401(k) allows higher contributions than a SEP-IRA because of the $23,500 employee deferral that doesn't exist in a SEP. The calculator above shows your exact comparison.

Does a CPA's Solo 401(k) affect the QBI deduction?

Solo 401(k) contributions reduce W-2 wages in an S-Corp, which is one of the QBI deduction factors. The net effect is typically favorable — the 401(k) deduction usually saves more than the marginal QBI deduction reduction. Model both scenarios before deciding your contribution amount.

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