Market Size, Demand & Patient Pool

The demand side of an allergy and immunology practice is unusually durable, because the underlying conditions are chronic and widespread. More than 100 million people in the United States live with some form of allergy, and roughly 25.7% of the population reported a seasonal allergy in the most recent CDC tabulation. Allergic rhinitis alone affects an estimated 60 million Americans, and more than 25 million live with asthma that often has an allergic driver.

Set this clinical reality against a growing treatment market. The US allergy treatment market was valued at about $7.55 billion in 2025 and is forecast to reach $15.56 billion by 2035, a 7.63% compound annual growth rate.

Source: Market Research Future / SNS Insider, 2025

Two structural trends matter for a new practice. First, allergen immunotherapy and the newer biologic therapies are pulling chronic patients into long-term, scheduled care rather than one-off visits, which improves revenue predictability. Second, food allergy is rising as a clinical and public-health challenge across both paediatric and adult populations, expanding the case mix a clinic can serve. The global allergy diagnostics and therapeutics market is growing at a double-digit rate through 2033 on the back of these same drivers.

Source: Grand View Research, 2025

A credible plan does not stop at the headline market number. It translates national prevalence into a catchment estimate: the practice's drive-time population, the share with treated allergic disease, referral relationships with local primary care and ENT, and the realistic number of immunotherapy patients the clinic can carry per provider. Those are the numbers a lender or a hospital partner will actually test.

The Competitive Field You Are Entering

Allergy and immunology is consolidating. National and regional groups such as Allergy Partners and AllerVie Health have rolled up independent practices, building scale in purchasing, billing infrastructure and payer negotiation. A solo founder is not competing with these groups on overhead; the founder competes on access, continuity of care and clinical reputation in a defined catchment. The plan should name the specific groups and hospital-employed allergists already serving the area, then state plainly where the new practice wins: shorter wait times for testing, a named physician who follows each immunotherapy patient through the full course, and same-week appointments that large systems struggle to offer.

It is also worth being honest about substitutes. Primary care physicians manage a large share of mild allergic rhinitis with over-the-counter and prescription antihistamines, retail clinics handle simple cases, and direct-to-consumer at-home IgE testing kits siphon off the curious-but-not-yet-symptomatic. None of these substitutes can deliver supervised immunotherapy, oral food challenges or biologic management, which is exactly why the plan should anchor positioning on the higher-acuity, recurring-care services that only a specialist clinic provides. Most operators stop at counting rival clinics; the number that actually drives this business is how many of the catchment's treated allergic-disease patients are currently managed sub-optimally by non-specialists and could be converted to specialist immunotherapy.

Who Your Patients Are

An allergy and immunology practice does not serve one buyer. It serves several overlapping patient segments, each with a different visit pattern, payer mix and lifetime value. The plan should size each one rather than collapsing them into a single average.

The referral network is part of the customer model. Primary care physicians, paediatricians, ENT surgeons and dermatologists feed an allergy clinic, and a plan that names the specific referrers in the catchment and the relationships the founder already holds reads far stronger than one that assumes patients arrive on their own. Self-pay food-allergy families and cash-pay environmental testing also matter in markets where commercial reimbursement is thin.

For a deeper view of adjacent specialist models, the pediatrics office and private clinic business plan template walk through related catchment and referral logic that applies here too.

Lifetime Value, Not Visit Value

The most important shift in how to think about these patients is from visit value to lifetime value. A subcutaneous immunotherapy course typically runs three to five years, with a build-up phase of weekly or twice-weekly injections followed by monthly maintenance. A single immunotherapy patient therefore represents dozens of scheduled touchpoints and a multi-year billing relationship, not a one-time consultation. When the plan models acquisition cost against that multi-year value rather than against a single visit, the marketing budget and referral-cultivation spend look entirely rational. A clinic that treats each patient as a one-off encounter will chronically under-invest in the referral relationships that actually compound.

Payer mix sits underneath all of this. Commercial insurance, Medicare and self-pay each carry different reimbursement, administrative burden and collection timing. A paediatric food-allergy practice in an affluent catchment may run a meaningful self-pay share for oral challenges and component testing, while an environmental-allergy practice in a Medicare-heavy market lives or dies on the 95165 conversion factor. The plan should state the assumed payer mix explicitly and test the forecast against a less favourable mix, because a clinic that only works at the optimistic payer split is not financeable.

Questions Founders Ask First

These are the exact questions allergists raise before they commit capital. Short answers here, fuller numbers below.

What It Costs To Open

Startup capital for an allergy and immunology practice is driven less by glamorous equipment and more by space and runway. A lean solo build-out begins near $298K in core CAPEX. A standard launch typically needs $1.0M-$1.1M of total funding once a cash cushion is included, and a full multi-room clinic with several providers reaches $1.8M-$2.3M.

Source: Financial Models Lab, 2025

UK private allergy clinics sit lower, roughly £90K to £420K, because many founders lease shared clinical space and outsource pathology rather than building a full lab on day one.

Line-Item Cost Breakdown

• Clinic build-out & renovation: $120K-$200K (£70K-£150K) - exam rooms, injection bay, lab space
• Immunotherapy lab & antigen prep equipment: $30K-$50K (£22K-£40K)
• Diagnostic equipment (spirometry, skin-test panels): $20K-$40K (£15K-£30K)
• EMR/EHR implementation & practice management: $20K-$30K (£14K-£24K)
• Emergency medical equipment (epinephrine, crash cart): $6K-$10K (£5K-£8K)
• Office furniture & fixtures: $15K-$25K (£11K-£20K)
• Working capital through credentialing (60-150 days): the largest hidden line, fund payroll and rent before claims pay

The hidden cost that derails first-year cash is timing, not price. Leasehold improvements run high, immunotherapy setup is modest, and the genuine danger is paying a physician, an NP/PA and an allergy nurse for months before insurance credentialing lets you bill. A first-year staffing budget near $605K against early revenue is normal, which is exactly why the cash cushion exists.

There is a meaningful difference between the three launch postures a founder can choose, and the plan should commit to one rather than blurring them. A lean solo launch keeps CAPEX near $298K to $450K by leasing finished clinical space, deferring the in-house lab and referring out complex testing at first. A standard launch in the $1.0M to $1.1M total-funding band builds the immunotherapy lab and a full exam-room set from day one and carries a larger cushion. A full launch at $1.8M to $2.3M opens multi-provider with several exam rooms, a dedicated infusion suite for biologics and a complete in-house testing capability. Each posture implies a different break-even patient count and a different debt-service load, so the choice is a financial decision, not an aesthetic one.

One line founders routinely forget is the pre-opening operating spend: rent and utilities during fit-out, recruitment and onboarding, the EMR configuration and staff training, and marketing to fill the appointment book before the doors open. These pre-opening costs sit outside the equipment list yet can run into the tens of thousands, and lenders expect to see them itemised rather than buried in a single contingency line.

Funding & SBA Lending Reality

Allergy and immunology practices fall under NAICS 621111 - Offices of Physicians (except Mental Health Specialists). Under SBA size rules, a physician office with annual revenue under $12 million counts as a small business, so almost every new clinic qualifies on size.

Source: NAICS.com, 621111

The SBA 7(a) loan is the workhorse here, offering up to $5 million for build-out, medical equipment, working capital and even practice acquisition or debt consolidation. Medical practices are a favoured category for SBA lenders because physician income is documentable and default rates are low relative to consumer-facing businesses. Many allergists pair a 7(a) loan with equipment financing for the immunotherapy lab so the loan principal covers build-out and runway.

Source: SBA7a.loans, medical practices

In the UK, founders combine the government-backed Start Up Loan (up to £25,000 per director at 6% fixed) with commercial healthcare lending and personal capital. Lenders on both sides of the Atlantic want the same thing: a forecast that proves you can service debt through the credentialing gap, not after it. The free template and the bespoke plan both build the loan-service coverage view that an SBA lender expects to see.

A practical funding structure many allergists use stacks three layers. The SBA 7(a) loan covers build-out and a working-capital tranche sized to the credentialing window. Equipment financing or a lease handles the immunotherapy lab and diagnostic kit, keeping that debt matched to assets with their own resale value. Personal capital or a physician practice-acquisition line funds the deposit and the first payroll cycles. Presenting this layered structure, with each layer mapped to a use of funds and a repayment source, signals to the lender that the founder understands debt service rather than simply asking for a single lump sum. The plan should also show the debt-service coverage ratio at the conservative payer mix, because that single ratio is what an underwriter circles first.

How The Money Is Made

Revenue in an allergy and immunology practice comes from five stacked lines, and the plan should model each separately because they behave differently:

• Consultations & evaluation: new-patient work-ups and follow-up visits
• Diagnostic testing: skin-prick panels, specific IgE blood testing, spirometry
• Allergen immunotherapy: antigen preparation (CPT 95165) plus injection administration, the recurring base
• Biologic therapy: in-office infusions and injections for severe asthma and chronic urticaria
• Oral food challenges & procedures: higher-acuity, higher-value scheduled visits

The line most founders under-model is immunotherapy. CPT 95165 covers the supervised preparation of antigens per dose. The 2025 Medicare conversion factor fell to $32.35, down 2.83% from $33.29 in 2024, and many payers cap reimbursement at up to 150 units per patient per year. Medicare also defines a dose as 1cc of extract and allows a maximum of ten billable doses from a 10cc multidose maintenance vial regardless of how many injections are drawn. Build the forecast on the per-unit rate and the annual cap together, not on a single blended number.

Source: ModuleMD, CPT 95165 2025 updates

Gross margins in this sector run roughly 15% to 31%, with net margins of 8% to 21% once a clinic is established. A solo practice staffing one physician, one NP/PA and one allergy nurse commonly projects first-year revenue near $900K and reaches a healthier margin as the immunotherapy panel matures into recurring antigen-prep billing.

Worked Example: A Solo Practice's First Full Year

Take a single-physician clinic that builds to about 250 active immunotherapy patients by month twelve. Those patients generate scheduled antigen-prep and injection revenue every month regardless of seasonal demand, which smooths the cash curve. Layered on top are new-patient consultations, testing panels and a handful of biologic patients. The recurring immunotherapy base is what turns a clinic from a feast-and-famine seasonal office into a predictable, financeable business, and it is the number a lender will stress-test first.

Walk the same clinic forward. In month one, with credentialing still in progress, billable revenue is near zero while the team is paid in full. By month four, credentialing clears and consultations and testing begin to convert. Through months five to nine, the build-up phase of immunotherapy generates frequent injection visits as new patients ramp their dosing. By month twelve, the maintenance cohort is large enough that monthly antigen-prep billing alone covers a meaningful share of fixed costs. This is why operating break-even can look early on a chart yet the business still needs a six-figure cushion: the chart measures the month revenue first exceeds variable cost, not the month cumulative cash turns positive.

The seasonality overlay matters too. Environmental-allergy demand spikes in spring and autumn, so a clinic that launches just before a pollen season fills its new-patient funnel faster than one that opens in mid-winter. A disciplined plan times the launch, the marketing push and the credentialing application so the practice is ready to bill when demand peaks rather than three months after it has passed. Founders who model a flat monthly revenue line miss this entirely and then scramble for working capital in the quiet months.

Cost Discipline That Protects The Margin

On the cost side, three levers protect the 8-21% net margin. The first is staffing cadence: hiring the allergy nurse and NP/PA in step with patient volume rather than all at once on day one. The second is antigen and supply procurement, where group purchasing and careful vial management reduce waste, given that Medicare allows only ten billable doses from a 10cc maintenance vial. The third is denial management; immunotherapy billing is notoriously error-prone, and a single mis-applied modifier or an exceeded annual unit cap can convert a profitable patient into a write-off. The plan should budget for a competent billing function, in-house or outsourced, as a margin-protection investment rather than an afterthought.

Credentials, Licensing & Compliance

Allergy and immunology is a credentialed specialty, so licensing is more involved than for a generic small business. Requirements differ sharply by jurisdiction.

United States

• State medical license (M.D. or D.O.) in the practice state
• American Board of Allergy and Immunology (ABAI) certification after fellowship
• CLIA certificate of waiver for in-office testing (~$180 biennial)
• Insurance credentialing with Medicare and commercial payers (60-150 days)
• OSHA bloodborne pathogen compliance and HIPAA safeguards
• Malpractice insurance, typically $1M per claim / $3M aggregate minimum

United Kingdom

• General Medical Council (GMC) full registration with a licence to practise under the Medical Act 1983
• Care Quality Commission (CQC) registration of the clinic as a regulated diagnostic and treatment provider, around £1,743 for a single-speciality single location in 2026
• Medical indemnity cover (MDU or MPS), with public and employers' liability in place before CQC registration
• Enhanced DBS check (~£50) and Information Commissioner's Office data-protection registration

Source: Team Care Compliance, CQC costs 2026

Other Jurisdictions

• Canada: licensure with the provincial College of Physicians and Surgeons; CRA Business Number; provincial billing number for the public/private mix
• EU: mutual recognition of professional qualifications under Directive 2005/36/EC; GDPR compliance and a Data Protection Officer for patient data
• UAE: clinician licence via DHA, DOH or MOHAP plus a facility licence; DED trade licence; professional indemnity cover

The compliance timeline is itself a financial input. In England the CQC process commonly takes 10-16 weeks, and in the US payer credentialing can run five months. Treat these as cash-flow events in the model, because the practice can be fully built and staffed yet legally unable to bill.

Operations, Staffing & Patient Acquisition

Operations are where an allergy practice protects its margin and its reputation at the same time. The clinical workflow has a few non-negotiable nodes: a safe injection bay with the staffing and emergency kit to manage the rare anaphylactic reaction during immunotherapy, a clean antigen-preparation area with strict vial labelling and expiry control, and a scheduling system that keeps build-up patients on cadence so courses are not abandoned. A plan that maps these workflows step by step reads as the work of an operator, not a hopeful applicant.

The Core Team

• Physician (allergist-immunologist): diagnosis, treatment planning, oral food challenges and biologic decisions
• Nurse practitioner or physician assistant: extends clinical capacity for follow-ups and routine management
• Allergy nurse: administers injections, prepares antigen vials and monitors the injection bay
• Front office & billing: scheduling, insurance verification and the denial management that immunotherapy demands

First-year staffing commonly lands near $605K across the clinical and administrative roles, with the physician salary the largest single line. The discipline is to phase hiring to patient flow, bringing on the second clinical provider only when appointment demand consistently outstrips a single schedule.

How New Patients Actually Arrive

Patient acquisition for a specialist clinic is dominated by referrals, not advertising. The most productive channel is a cultivated relationship with local primary care physicians, paediatricians, ENT surgeons and dermatologists who send the patients they cannot fully manage. The plan should describe how the founder will earn those referrals: fast, legible consult letters back to the referrer, easy direct-booking, and visible sub-specialty depth in food allergy or biologics. Secondary channels include a search-optimised website that captures high-intent queries such as testing and immunotherapy, self-pay food-allergy families researching oral challenges, and community education through schools and employers in catchments with high paediatric allergy prevalence. The acquisition model should connect each channel to a cost per acquired patient and, crucially, to the multi-year value of an immunotherapy course rather than a single visit.

For founders who want the marketing and referral plan written to investor standard, the research and content package builds the channel economics and the referral-cultivation calendar directly into the plan.

Key Terms For Your Plan

A handful of terms recur throughout an allergy and immunology practice plan. Define them once so investors and lenders read the financials the way you intend.

• CPT 95165: the billing code for supervised preparation of antigens for allergen immunotherapy, charged per dose; the recurring-revenue engine of the practice.
• Maintenance vial: the concentrated antigen vial a patient progresses to after build-up; Medicare allows up to ten billable doses per 10cc vial.
• Build-up phase: the initial weeks of immunotherapy with frequent, escalating injections before a patient reaches maintenance dosing.
• CLIA waiver: the certificate that lets a practice run simple in-office tests; required before billing for those tests.
• Credentialing: the payer enrolment process, taking 60-150 days, during which the practice cannot bill insured patients.
• Biologics: targeted injectable or infused therapies for severe asthma and chronic urticaria, a high-value scheduled service line.
• Tenant-improvement allowance: the landlord contribution to build-out, negotiated into the lease, that directly reduces CAPEX.

Five Mistakes That Sink New Practices

Across allergy and immunology launches, the same avoidable errors recur. A good plan pre-empts each one.

• Under-building the immunotherapy line. The antigen-prep base billed under CPT 95165 is the recurring revenue engine. Founders who treat immunotherapy as an afterthought build a seasonal office instead of a financeable practice.
• Ignoring payer caps and the falling conversion factor. Modelling 95165 at last year's rate, or without the per-patient annual unit cap, overstates revenue. The 2025 conversion factor of $32.35 and the up-to-150-unit cap belong in the forecast.
• Treating build-out as a fixed number. Leasehold improvements run 40-50% of CAPEX and swing widely with location and condition. Negotiate a tenant-improvement allowance before signing the lease.
• Opening before credentialing completes. Paying a full clinical team for 60-150 days while claims cannot be billed is the most common cash crisis. Size the cushion to the credentialing gap, not the first patient.
• Modelling one patient type. Rhinitis, food allergy, asthma, chronic urticaria and immunodeficiency carry different acuity, payer mix and value. Collapsing them into one average hides both risk and opportunity.

Inside The Sample Plan

Here is the structure and the financial outputs a buyer receives. These visual mockups are generated from the same assumptions used throughout this page.

What The Template Includes

Every Avvale business plan template ships pre-structured for an allergy and immunology practice, with the sections lenders and hospital partners expect:

• Executive Summary - the practice at a glance, written to hold an SBA loan officer in the first 60 seconds
• Company Overview - legal structure, ownership, location and the founder's clinical background
• Industry Analysis - allergy prevalence, treatment-market growth and immunotherapy trends with citations
• Patient & Referral Analysis - segment sizing and the referral network feeding the clinic
• Competitor Analysis - local allergy and ENT mapping and your clinical differentiation
• Marketing Plan - referral cultivation, self-pay testing and digital intent capture
• Operations Plan - immunotherapy workflow, credentialing timeline and staffing
• Management Team - founder bio, clinical staff plan and advisory support

The optional Financial Forecast add-on (included in the $300/£250 and $1,000/£800 packages) provides a 5-year Excel model with income statement, cash flow, balance sheet, break-even analysis and the CPT 95165 immunotherapy build that anchors the revenue line.

Frequently Asked Questions

Useful Links & Resources

Related Avvale guides and references for founders planning an allergy and immunology practice.

• Free business plan templates library
• Walk-in clinic business plan template
• Work with an Avvale business plan writer
• Avvale on LinkedIn