An oncologists email list that knows which oncologist you mean

An oncologists email list spans five registry codes filed under four specialties, so the word oncology alone both misses physicians and catches the wrong ones. The AAMC counted 18,612 active physicians in hematology and oncology and 5,894 in radiation oncology in 2024. The Bureau of Labor Statistics publishes no separate occupation for oncologists.

Oncologists in the official counts

NPPES downloadable file, September 2026, CMS; active NPIs only, primary taxonomy only; counted by Premium Data on 3 October 2026.

Why the AAMC rows and the NPPES row cannot be compared one to one.

• Hematology. The AAMC methods page builds its hematology and oncology group from three categories: hematology, hematology/oncology and medical oncology. The NPPES row leaves out the code for hematology alone. The AAMC figure is therefore wider on that side.
• Surgeons and gynecologists. The NPPES row includes surgical oncology and gynecologic oncology. The AAMC dashboard only shows specialties with more than 2,500 active physicians, and neither appears among them. The NPPES row is wider on that side.
• People and identifiers. The AAMC counts physicians who finished training and work more than 20 hours a week. NPPES counts active identifiers by the primary code each provider chose. Dates differ too: 2024 against September 2026.

The five codes, and the oncologists left out

The registry uses the taxonomy of the National Uniform Claim Committee, version 26.1, in effect since 1 July 2026. No classification is called oncology. Each oncology code hangs from another specialty.

Also out: oncology nurses (163WX0200X), oncology pharmacists (1835X0200X), oncology clinical nurse specialists (364SX0200X) and oncology dietitians (133VN1301X). They are not physicians. Oncology clinics carry organization codes of their own (261QX0200X, and 261QX0203X for radiation): those are companies, reached with a company line. For the physician lists that sit beside this one, see the role index.

Where oncologists practice, and what each source shows

• The NPPES file gives the name, the codes, and one reported practice address and phone. It says nothing about which cancer center or network the oncologist belongs to, and gives no email.
• The National Cancer Institute lists 74 NCI-Designated Cancer Centers in 37 states and the District of Columbia (page updated 20 May 2026): 58 hold its top designation, 8 are clinical cancer centers and 8 are basic laboratory cancer centers. It names institutions, not physicians.
• The American College of Surgeons says that nearly 1,400 hospitals and cancer centers in the US are accredited by its Commission on Cancer, and that they treat cancer with surgeons, radiologists, pathologists, radiation oncologists and medical oncologists together. A program list, not a physician list.
• The AAMC dashboard shows the work setting in 2024: 66.4% of hematology and oncology physicians in office-based practice, 15.2% hospital-based full time, 4.5% in research. Radiation oncology is more hospital-bound, at 20.6% hospital-based full time.
• The BLS cannot help with a count: oncologists have no occupation code of their own in its May 2025 list.

How the list gets built, in five lines

• Choose which of the five codes you want, and whether hematologists who do not treat cancer belong.
• Count them in NPPES, primary taxonomy only.
• Tie each oncologist to a practice, a hospital program or a cancer center.
• Find a phone that reaches them and a work email when it exists; confirm they are still there.
• Take out your current clients.

Each step and what breaks at it is on the page about the full method.

What 24,506 oncologists take to reach

The two AAMC groups that match the core of the target add up to 24,506 active physicians in 2024 (18,612 plus 5,894). Working from that figure:

• 18,612 specialty checks, one per hematology and oncology physician, because the AAMC group mixes oncologists with hematologists who never treat cancer;
• 24,506 NPI lookups, to read the primary code and the practice location;
• 74 cancer center directories to read, one per NCI-designated center, and nearly 1,400 accredited hospital programs to call if you want the program and not only the practice;
• 24,506 phone searches, and the same number of checks that the oncologist still works where the line says.

Oncology traps a buyer should know

Hematologists inside, or outside

Medical oncology, hematology-oncology and hematology alone are three different codes. A drug or service aimed at cancer patients does not interest a hematologist who treats clotting disorders. The reverse holds for a product built for blood disorders. Say which side you want: the codes allow the split, the AAMC figure does not.

Radiation oncologists buy for a different room

Radiation oncologists treat with radiation equipment and are filed under radiology. A buyer selling cancer drugs rarely needs them. A buyer selling radiation therapy services needs them first. One word, oncologist, covers two markets.

An academic title on the line

At a cancer center tied to a university, an oncologist can carry an academic title, such as associate professor, and a clinical one. If your filters accept only oncologist or medical director, academic lines drop out. Decide which titles you accept before the count.

The practice is not the person

Oncologists can see patients in infusion centers and satellite clinics, and each clinic can hold an organization NPI of its own. The number of the clinic reaches nurses and schedulers. For a purchase, the person who answers is often a practice administrator, a cancer program director or the director of pharmacy, who has a say in which drugs are stocked. Ask for those roles by name if they are your target.

What Premium Data does on an oncology order

• One line per company or per person: the practice, center or clinic (name, address, main phone, website), or the oncologist (name, title, organization, a phone that reaches them, work email when it exists).
• Built the day the order is placed, on the codes and the split you chose.
• Three checks: the organization, the oncologist, and whether the oncologist still practices there.
• Billing covers only lines delivered with a phone number, and stops at the ceiling you set.
• A wrong line is refunded at its price, on proof (call recording, hard bounce or public profile), within thirty days of delivery.
• Counting is free, during a 30 minute call, and you call one oncologist of the file with us before any payment.

The federal rules for calling and emailing medical practices are on our United States page.

In short, three oncology facts with a date

• On 3 October 2026, the NPPES file of September 2026 listed 30,920 active individual NPIs whose primary taxonomy is one of five oncology codes, filed under internal medicine, radiology, surgery and obstetrics and gynecology (CMS, counted by Premium Data).
• On 20 May 2026, the National Cancer Institute listed 74 NCI-Designated Cancer Centers in 37 states and the District of Columbia (cancer.gov, read on 3 October 2026).
• The AAMC counted 18,612 active hematology and oncology physicians and 5,894 radiation oncologists in the United States in 2024 (AAMC U.S. Physician Workforce Data Dashboard, read on 3 October 2026).