Allergy practice ownership economics: infusion suite, immunotherapy, and biologic margins

May 6, 2026 · Pouyan Golshani, MD, Interventional Radiologist

Allergy is one of the highest-margin private practice specialties. Here’s the buy-and-bill, immunotherapy, and biologic infusion economics that drive it.

That statement is true, but it’s only half the story. The real economic leverage in an allergy practice isn’t just about the gross margin on a vial of Xolair or the reimbursement for a venom immunotherapy tray. It’s about the net, after-tax dollars that land in your personal bank account. As a practice owner or an employed physician, mastering the tax and operational structure around your income is just as critical as mastering the clinical side of atopic dermatitis or asthma. The difference can be tens, or even hundreds, of thousands of dollars per year.

We’ll break down the core financial strategies that successful allergists use to build wealth, whether they own the practice or are building a career as a high-earning W-2 physician. These aren’t generic tips; they are specific, actionable tax and savings frameworks. You can find more resources in the allergy and immunology free tools hub, but this article focuses on the high-impact strategies that move the needle most.

The 199A QBI Deduction: Protecting Your Practice’s Biggest Tax Break

For allergists who own their practice as a pass-through entity (like an S-corp or LLC), the Section 199A Qualified Business Income (QBI) deduction is arguably the most valuable tax break available. It allows you to deduct up to 20% of your qualified business income, a direct reduction of your taxable income. However, there’s a critical catch: as a physician, your practice is considered a “Specified Service Trade or Business” (SSTB). This means the deduction begins to phase out and eventually disappears entirely once your taxable income crosses certain thresholds.

For 2026, those thresholds are projected to be around $394,000 for single filers and $787,000 for those married filing jointly. Many successful practice owners will find themselves bumping up against or exceeding these limits. Losing this deduction is like taking a 20% pay cut on a huge chunk of your income.

The strategy here is proactive AGI (Adjusted Gross Income) management. The goal is to legally reduce your taxable income to stay below the phase-out range. Here’s the sequence:

Max Out Pre-Tax Retirement Accounts: This is the first and most powerful lever. For an S-corp owner, this means maximizing both your employee and employer contributions to a 401(k), potentially reaching the $69,000 limit (for 2024, indexed for inflation). If you have a spouse who can be employed by the practice, they can do the same.
Utilize a Cash Balance Plan: For highly profitable practices, a cash balance plan is a type of defined-benefit pension that allows for massive pre-tax contributions, often exceeding $100,000 per year, depending on your age and income. This can dramatically lower your AGI.
Bunch Charitable Donations: Instead of donating a set amount each year, “bunch” several years’ worth of donations into a single year using a Donor-Advised Fund (DAF). A $100,000 contribution to a DAF provides a $100,000 deduction in the current year, potentially pulling you back under the 199A threshold.

The Trap to Avoid: The most common mistake is reactive planning. You can’t wait until March of the following year to discover you’ve phased out of the deduction. This requires quarterly check-ins with your CPA to project your income and make adjustments. A single, ill-timed bonus or asset sale can push you over the cliff. Modeling these scenarios is complex, which is where tools like the physician finance hub can help by mapping out how different income and deduction scenarios impact your eligibility for major tax credits and deductions like 199A.

Unlocking Deductions with 1099 Side Income

The Tax Cuts and Jobs Act of 2017 (TCJA) was a blow to W-2 physicians. It eliminated the ability to deduct unreimbursed business expenses—things like your state license fees, DEA registration, board exam fees, CME travel, scrubs, and home office equipment. For many employed allergists, this meant thousands of dollars in lost deductions every year.

The fix is to generate even a small amount of 1099, or independent contractor, income. This creates a Schedule C (Profit or Loss from Business) on your tax return, which acts as a vehicle for deducting all those professional expenses that are no longer deductible against your W-2 salary. The income can come from anywhere: telemedicine shifts, expert witness reviews, medical directorships, or consulting for a local biotech startup.

Here’s how it works in practice:

Generate 1099 Income: You perform a few chart reviews and earn $5,000, for which you receive a 1099-NEC.
Create a Schedule C: You report this $5,000 as gross revenue for your “consulting business.”
Deduct Expenses: Now, you can deduct the “ordinary and necessary” expenses for this business. This includes a portion of your cell phone bill, home internet, a new laptop, your $888 DEA fee, your state license renewal, and the cost of that allergy conference in San Diego.

The Trap to Avoid: You cannot deduct more expenses than you have income and generate a loss to offset your W-2 wages unless you meet complex “material participation” rules. The goal isn’t to create a massive paper loss. The goal is to turn non-deductible expenses into deductible ones. If you have $6,000 in professional expenses and $5,000 in 1099 income, you can deduct $5,000 of those expenses, effectively making your side-gig income tax-free and “rescuing” $5,000 worth of deductions you would have otherwise lost completely. Any remaining expenses can’t be used, but you’re still far ahead.

The Solo 401(k): Supercharging Your Side-Gig Savings

Once you have that 1099 income stream, you unlock one of the most powerful retirement savings vehicles available: the Solo 401(k), also known as an Individual 401(k). It’s designed for self-employed individuals, and it allows you to contribute as both the “employee” and the “employer.”

This dual contribution structure is key. As the “employee,” you can contribute up to 100% of your self-employment compensation, not to exceed $23,000 (in 2024). As the “employer,” you can contribute an additional 20% of your net self-employment earnings. The total contributions from both sources cannot exceed $69,000 (for 2024). This is separate from and in addition to your W-2 job’s 401(k) or 403(b).

Let’s take an example. Dr. Smith is an employed allergist who also has a medical directorship that pays her $50,000 a year on a 1099.

She already maxes out her employee contribution to her hospital’s 401(k) ($23,000).
With her $50,000 of 1099 income, she can open a Solo 401(k).
She cannot make another “employee” contribution, as she’s already maxed that at her primary job.
However, she can make an “employer” contribution of 20% of her net self-employment income. After deducting one-half of self-employment taxes, her net income is roughly $46,425. She can contribute 20% of this, which is about $9,285, into her Solo 401(k) as a pre-tax contribution.

This directly reduces her taxable income by over $9,000. Furthermore, many Solo 401(k) plans allow for Roth contributions and after-tax contributions, opening the door for the “Mega Backdoor Roth IRA” strategy on your side income.

The Trap to Avoid: The Solo 401(k) must be established before the end of the calendar year (December 31) to make contributions for that year. Many physicians wait until tax time in April, only to find out it’s too late. You can still fund it up to the tax deadline, but the plan itself must be opened by year-end. Don’t miss the deadline.

The HSA Triple-Stack: Your Ultimate Stealth Retirement Account

The Health Savings Account (HSA) is the most tax-advantaged account in the entire US tax code, yet it’s often misunderstood and underutilized by physicians. It offers a unique triple tax benefit:

Contributions are tax-deductible (pre-tax).
The money grows tax-free inside the account.
Withdrawals for qualified medical expenses are tax-free.

Most people use their HSA like a checking account for medical bills. This is a mistake. The optimal strategy is to treat it as a long-term investment vehicle—a “stealth IRA.”

Here’s the “triple-stack” strategy:

Max It Out: Contribute the maximum family amount every year. For 2026, this is projected to be around $8,750. If you are over 55, you can add another $1,000 catch-up contribution.
Invest It: As soon as the money hits the account, invest it in low-cost, broad-market index funds. Do not let it sit in cash. The goal is long-term, tax-free growth.
Save Receipts, Pay Out-of-Pocket: Pay for all current medical expenses (copays, prescriptions, dental) with a credit card or cash, not from the HSA. Scan and save every single medical receipt digitally in a dedicated folder. Decades from now, in retirement, you can withdraw money from your HSA tax-free against this accumulated pile of old receipts. It essentially becomes a tax-free emergency fund or source of retirement income.

After age 65, you can also withdraw from your HSA for any reason, not just medical. The withdrawals will be taxed as ordinary income, just like a traditional IRA, but you still get the benefit of the initial tax deduction and decades of tax-free growth. It’s a can’t-lose proposition.

The Trap to Avoid: Not all HSA providers are created equal. Many default bank-offered HSAs have high fees and poor investment options. You must seek out a custodian that offers a good selection of low-cost index funds and allows for first-dollar investing. Look for providers like Fidelity or Lively, which are known for their physician-friendly platforms.

Advanced Strategy: Oil & Gas Intangible Drilling Costs (IDCs)

For high-income practice owners looking for large, immediate deductions, direct participation in oil and gas drilling partnerships can be an option, though it comes with significant risk and complexity. The primary tax benefit comes from the deduction for Intangible Drilling Costs (IDCs). These are the non-salvageable costs of drilling a well, such as labor, fuel, and supplies.

Under the tax code, investors can deduct 65-80% of their investment in the very first year. For example, a $100,000 investment could generate an immediate $80,000 tax deduction. For an allergist in a high tax bracket, this could translate to over $30,000 in tax savings, effectively lowering the at-risk capital in the investment.

However, this is not a simple or low-risk strategy. The wells can be dry, resulting in a total loss of investment. The income stream, if any, is depleting. And there’s a major tax complication.

The Trap to Avoid (The AMT): The IDC deduction is a “tax preference item” for the Alternative Minimum Tax (AMT). The AMT is a parallel tax system designed to ensure high-income earners pay at least a minimum amount of tax. A large IDC deduction can easily trigger the AMT, clawing back a significant portion of the tax savings you were trying to achieve. Furthermore, these deals are often illiquid and subject to high fees. This strategy should only be considered by sophisticated investors with a high-risk tolerance and in close consultation with a CPA who specializes in both physician finance and energy sector investments. It is not for the faint of heart.

Building a financially successful allergy practice—and a successful career—is about more than just clinical excellence and billing codes. It requires a sophisticated understanding of the tax code and a proactive approach to financial planning. By integrating strategies like AGI management for the 199A deduction, leveraging 1099 income, and maximizing tax-advantaged accounts, you can ensure that the high margins of your specialty translate into durable, long-term wealth. If you are looking to model these strategies or explore the economics of practice ownership further, you can talk to GigHz about practice ownership.