Tax Rate Arbitrage: How Smart Owners Move Income to Lower Brackets

Tax planning is a game of arbitrage. You take a dollar that would be taxed at one rate and you move it to a place where it is taxed at a lower rate. That is most of what real tax strategy actually does.

Once you see tax planning through the arbitrage lens, the alphabet soup of strategies (S-Corps, 1031s, QSBS, retirement plans) stops looking random. Every one of them is a way to move income across a rate boundary.

Three Kinds of Rate Boundaries

There are three places where tax rates change. Each one is a potential source of arbitrage.

Between ordinary income and capital gains. Ordinary rates top out at 37% federal plus 3.8% net investment income tax. Long-term capital gains top out at 20% plus 3.8%. On a $500,000 gain, that difference is $85,000. Structures that convert ordinary income into capital gains, like QSBS, real estate appreciation, and equity compensation, capture this spread.

Between taxable entities and tax-advantaged accounts. A 401(k), a SEP IRA, a defined benefit plan, or an HSA moves income out of the top marginal bracket today and parks it in a tax-deferred or tax-free wrapper. An owner in the 37% bracket who contributes $66,000 to a solo 401(k) saves roughly $24,000 in federal tax this year.

Between high-income years and low-income years. A business owner who clears $800,000 in a banner year and $150,000 the next year pays the same lifetime income but a lot more tax if nothing moves between the two. Strategies that defer income from the big year or accelerate deductions into the big year capture the arbitrage between rates.

Where the Rate Spread Actually Lives

The biggest spreads in the code right now show up in three places.

Self-employment tax versus distributions. Pass-through profit taxed as self-employment income pays 15.3% on the first $168,600 and 2.9% above that. The same profit taxed as an S-Corp distribution pays zero self-employment tax. An owner with $250,000 in profit who runs it through an S-Corp with an $80,000 salary saves about $20,000 in self-employment tax. That is pure arbitrage on the structure lever.

Ordinary income versus long-term capital gains on real estate. A property held for one year and a day and sold qualifies for long-term gains. A property depreciated and sold triggers recapture at 25%, but the gain above basis is still long-term. Combined with a 1031 exchange, you can defer the gain entirely and reset the basis when the replacement property later transfers at death with a step-up. That is multi-decade arbitrage on the timing lever.

Federal brackets versus state brackets. An owner who lives in a 9.3% state and moves to a 0% state before a $5 million sale saves $465,000 in state tax. The move has to be real, well-documented, and done before the deal, but the arbitrage is large enough to justify the work.

The Trap in Rate Arbitrage

Every arbitrage carries risk. The rate spread might close. The transaction might be recharacterized. The rule you relied on might change.

The rules around arbitrage are dense because the savings are real. The IRS spends real time closing loopholes that created big rate spreads. Anything that looks too easy probably is.

How to Think About It in Your Business

Every year, the question is the same. Where are the rate differences in your financial life, and which ones are worth capturing?

Start with the biggest dollar amount. For a business owner, that is usually the structure of the business and the sale of the business. Both create multi-decade arbitrage.

Then look at timing. Are you in a high-income year that warrants acceleration of deductions or retirement plan contributions? A low-income year that warrants a Roth conversion or harvesting gains at the 0% bracket?

Tax planning done well is a series of small moves that each capture a rate spread. Stacked over a career, those moves pay for themselves many times over.