Cash Balance Plan for Physicians: Shelter $150K–$300K Beyond the Solo 401(k)

If you're a practice owner or locum physician netting $300,000–$600,000, the solo 401(k) stops at $72,000 combined. That's a meaningful shelter — but at a 37% marginal federal rate, there's a lot of taxable income left over. A cash balance plan stacks on top of the solo 401(k) and lets physicians contribute $100,000 to $300,000+ more per year into a tax-deferred defined benefit plan, depending on age. For a 50-year-old netting $500K, the combined tax savings can exceed $100,000 in a single year.

What Is a Cash Balance Plan?

A cash balance plan is a type of defined benefit plan that looks like a defined contribution account from the participant's perspective. Each year the employer credits your "account" with a pay credit (a percentage of compensation) plus an interest credit (a fixed or variable rate set in the plan document — often 3–5%). You see a running balance, just like a 401(k).

The key difference from a 401(k): the benefit at retirement is defined, not the contribution. The IRS limits how large that benefit can be — the 2026 maximum annual benefit at retirement is $290,000 per year, or roughly a $3.6M lump sum.¹ An actuary works backwards from that ceiling to determine what you can contribute each year, based on your current age, years until retirement, and the plan's interest crediting rate.

Because older participants have fewer years for contributions to compound to that benefit limit, age dramatically increases the allowable annual contribution. A physician who starts a cash balance plan at 55 instead of 45 can contribute substantially more each year.

Why It's Particularly Powerful for Physicians

Most high-income professionals face the same 401(k) ceiling. What makes cash balance plans especially compelling for physicians is a combination of factors that don't apply to most occupations:

• Compressed earning window. Physicians start earning high incomes at 30–35 after training. That's 10–15 fewer peak earning years compared to a business owner who started at 22. A cash balance plan accelerates tax-sheltered accumulation to compensate for the late start.
• High marginal rates. A physician netting $500K is in the 37% federal bracket plus state income tax. Every dollar sheltered in a cash balance plan avoids tax at that rate today and is taxed at retirement when income (hopefully) drops. The spread between today's rate and retirement rate is the core return.
• 1099/practice income flexibility. Hospital-employed physicians rarely have access to this vehicle. But locum physicians with 1099 income and practice owners — a large and growing share of physicians — can set one up directly, often with their S-corp or PLLC as the plan sponsor.
• No competing 457(b) option. If you're self-employed, you don't have a hospital 457(b) to fall back on. The cash balance plan fills that gap and then some.

How Much Can You Contribute?

There is no single annual "contribution limit" for a cash balance plan the way there is for a 401(k). The IRS limits the ultimate benefit, and an actuary works backwards to determine what annual contribution reaches — but does not exceed — that limit by your retirement date. Contributions increase with age because there are fewer years for money to grow.

The table below shows approximate maximum annual cash balance contributions for a physician planning to retire at age 65, using a 5% interest crediting rate. These are illustrative ranges; your actual limit requires an actuarial calculation.²

The 2026 compensation limit for plan purposes is $360,000.¹ If your net income from the practice exceeds that, contributions are calculated against the $360K cap. An actuary will model the specific numbers for your age, income, and chosen retirement age.

Stacking With Your Solo 401(k)

The cash balance plan doesn't replace your solo 401(k) — it stacks on top of it. In 2026, a physician who maxes both can shelter:

For a physician in the 37% federal bracket plus a 5% state rate (42% combined), sheltering $250,000 saves approximately $105,000 in taxes in a single year. That's not a small number. The plan costs roughly $2,000–$5,000/year to administer. The math works overwhelmingly in the physician's favor.

Important: the combination of 401(k) + cash balance contributions cannot exceed certain IRS testing limits (commonly called the 31% rule in some plan designs). Your actuary will design the plan to stay within those limits. In practice, a physician netting $360K–$500K can almost always max both simultaneously.

Who It Makes Sense For

Cash balance plans are not for everyone. They involve administration costs, annual funding commitments, and actuarial complexity. They make the most sense when:

• Net practice income is $250,000+. Below that, the setup cost relative to tax savings may not justify it. At $300K+, the math strongly favors moving forward.
• You expect to maintain high income for at least 3–5 years. Cash balance plans generally require annual contributions. If your income drops dramatically — practice sale, moving to part-time — the required contribution can create a cash flow strain. Consult your actuary before major income changes.
• You are the primary or sole owner. If you have employees, the plan must cover them too at a minimum contribution level. This can make plans expensive for practices with many non-physician staff (see below). Solo practitioners and small physician groups are the best fit.
• You have maxed out your 401(k) and are looking for the next shelter. Cash balance is step two, not step one. Solo 401(k) first; cash balance second.

If you're a hospital-employed attending without 1099 income, cash balance plans likely aren't available to you — your employer is the plan sponsor and that's not in most hospital contracts. The path for you runs through 403(b), 457(b), backdoor Roth, and taxable investing. See the 457(b) guide for that track.

Setup and Annual Administration Costs

Running a cash balance plan requires hiring a third-party administrator (TPA) and actuary who specialize in defined benefit plans. Typical costs:

• Setup fee: $1,500–$3,000 (one-time)
• Annual administration and actuarial work: $1,500–$4,000/year
• Plan termination (if you ever shut it down): $1,500–$3,000
• Investment management: Plan assets are invested separately from your 401(k) — typically in a separate brokerage account in the plan's name

Total annual drag: roughly $2,000–$5,000 for a solo physician. At a 42% combined tax rate on contributions of $150,000–$250,000, the first-year tax savings dwarf the cost by 20:1 or more. The administration costs don't change the decision for most physicians in this income range.

What Happens to the Money?

When you retire, terminate the plan, or sell your practice, the cash balance plan account balance can be rolled directly into a traditional IRA. This is one of the advantages over non-governmental 457(b) plans — you control the rollover and can continue tax-deferred growth indefinitely, subject to RMD rules at age 73 (or 75 if born in 1960 or later, per SECURE 2.0).³

At rollover, the balance transfers at fair value. The interest crediting rate inside the plan is replaced by whatever your IRA investments earn. Most physicians roll into a self-directed IRA and invest in low-cost index funds.

You can also take a lump-sum distribution at termination and pay ordinary income tax (plus 10% penalty before age 59½). Almost nobody does this — the IRA rollover is nearly always the right choice.

One timing consideration: plan termination requires IRS notification and a final actuarial valuation. Budget 6–12 months if you're planning a termination around a practice sale. Factor this into your deal timeline.

What if You Have Employees?

If your practice employs non-physician staff, a cash balance plan becomes more complex. ERISA requires that the plan benefit a broad class of employees — you generally can't set it up just for yourself and exclude the receptionist and medical assistant.

The minimum coverage test requires that either 70% of all non-highly compensated employees (NHCEs) benefit from the plan, or the plan passes a ratio percentage test. In practice, this means you must provide some defined benefit credit to eligible employees, which adds to the annual contribution cost.

For a physician with 3–5 employees, a plan actuary can often design a structure where physician contributions are still dramatically higher than staff contributions — the math still works at net incomes above $350K. For larger practices, the analysis gets more practice-specific. This is a conversation to have with a TPA who specializes in physician practices before committing.

Related Guides

• Physician Tax Strategy: Solo 401(k), S-Corp, and Beyond
• Physician Retirement Catch-Up Calculator
• S-Corp Election Calculator for Physicians
• 457(b) Deferred Compensation: Hospital Physician Guide
• Locum Tenens Financial Planning: Taxes, Solo 401(k), and More