National totals
| Active NPI records | 5,249 |
| Registered sole proprietors | 788 (15.0%) |
| NUCC taxonomy code | 207K00000X |
| Grouping | Allopathic & Osteopathic Physicians |
What this specialty covers
An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Selected examples of such conditions include asthma, anaphylaxis, rhinitis, eczema, and adverse reactions to drugs, foods, and insect stings as well as immune deficiency diseases (both acquired and congenital), defects in host defense, and problems related to autoimmune disease, organ transplantation, or malignancies of the immune system.
Reading the sole-proprietor share
For this specialty, the sole-proprietor share describes the portion of active NPI records flagged as sole proprietors in NPPES: 788 records, or 15.0%. It can help address private-practice questions, but it is an imperfect proxy because the field is self-reported and may not capture practice ownership, employment arrangements, group structure, or clinical workload.
By state
| State | Active NPIs | Sole proprietors | Share |
|---|---|---|---|
| California | 537 | 90 | 16.8% |
| Texas | 489 | 69 | 14.1% |
| New York | 440 | 91 | 20.7% |
| Florida | 344 | 78 | 22.7% |
| Pennsylvania | 239 | 38 | 15.9% |
| Ohio | 187 | 26 | 13.9% |
| New Jersey | 186 | 43 | 23.1% |
| Illinois | 186 | 33 | 17.7% |
| North Carolina | 182 | 12 | 6.6% |
| Michigan | 181 | 34 | 18.8% |
| Maryland | 177 | 32 | 18.1% |
| Virginia | 160 | 20 | 12.5% |
| Georgia | 138 | <11 | not reported |
| Massachusetts | 135 | 11 | 8.1% |
| Colorado | 132 | 14 | 10.6% |
| Tennessee | 101 | 12 | 11.9% |
| Arizona | 101 | 13 | 12.9% |
| Indiana | 100 | <11 | not reported |
| Washington | 100 | <11 | not reported |
| Kentucky | 82 | <11 | not reported |
| Louisiana | 81 | 20 | 24.7% |
| Minnesota | 79 | <11 | not reported |
| Wisconsin | 77 | <11 | not reported |
| Connecticut | 76 | 15 | 19.7% |
| South Carolina | 73 | <11 | not reported |
| Missouri | 59 | <11 | not reported |
| Oregon | 48 | 13 | 27.1% |
| Alabama | 41 | <11 | not reported |
| Iowa | 40 | <11 | not reported |
| Kansas | 39 | <11 | not reported |
| Oklahoma | 36 | <11 | not reported |
| Mississippi | 36 | <11 | not reported |
| Arkansas | 34 | <11 | not reported |
| Utah | 31 | <11 | not reported |
| Nevada | 30 | <11 | not reported |
| New Mexico | 29 | <11 | not reported |
| District of Columbia | 29 | <11 | not reported |
| West Virginia | 26 | <11 | not reported |
| Nebraska | 26 | <11 | not reported |
| Hawaii | 21 | <11 | not reported |
| Montana | 19 | <11 | not reported |
| New Hampshire | 19 | <11 | not reported |
| Rhode Island | 15 | <11 | not reported |
| Delaware | 13 | <11 | not reported |
| Alaska | 11 | <11 | not reported |
New NPI registrations by year
| Year first enumerated | NPIs |
|---|---|
| 2016 | 101 |
| 2017 | 79 |
| 2018 | 92 |
| 2019 | 94 |
| 2020 | 105 |
| 2021 | 45 |
| 2022 | 32 |
| 2023 | 54 |
| 2024 | 50 |
| 2025 | 54 |
Counts reflect the year each NPI was first issued, among records still active today. The final year is partial: this data covers through 2026-01-11.
Data notes
- The sole-proprietor field is self-reported by the provider in NPPES and is an imperfect proxy for private practice.
- A sole-proprietor count shown as <11 is suppressed: the true value is below 11, which could include zero.
- An NPI record is not necessarily a unique physician, and taxonomy data may not reflect current clinical focus or workload.
- State counts use NPPES reporting information and may not represent where care is delivered.
- Providers are counted once, by their primary taxonomy code only.
Common questions
How many Allergy & Immunology Physicians are there in the US?
There are 5,249 active NPI records nationally with Allergy & Immunology Physician as the primary taxonomy. This is a count of NPI records, not necessarily a count of distinct physicians or practices.
How many Allergy & Immunology Physicians are in private practice?
A total of 788 records, or 15.0%, are flagged as sole proprietors in NPPES. This self-reported flag is an imperfect proxy for private practice.
Which states have the most Allergy & Immunology Physicians?
The largest state counts are California (537), Texas (489), New York (440), Florida (344), and Pennsylvania (239). These are NPI record counts associated with each state.
How many Allergy & Immunology Physician NPIs were first enumerated in recent years?
NPIs first enumerated in the most recent full years available were 54 in 2023, 50 in 2024, and 54 in 2025. Enumeration year indicates when an NPI record was first issued, not necessarily when a physician began practicing.
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