Company lists · Data refreshed September 2026

Top 25 Internal medicine practices based in the United States

RevenueBase identified 3,469 internal medicine practices headquartered in the United States as of September 2026 and tracks 49,060 professional contacts across them, including 10,788 with verified work emails. New York is the largest hub.

This list covers internal medicine practices headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 20, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review
3,469Companies
49,060Contacts tracked
10,788Verified emails
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The 25 largest internal medicine practices based in the United States

Ranked by team size
Top 25 of 3,469 internal medicine practices based in the United States, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to internal medicine practices: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceBurlington, MA, United StatesHQ checked Sep 20, 20265,001-10,0004,441 contacts →

Partial evidence

“Lahey Hospital & Medical Center, part of Beth Israel Lahey Health, is a physician-led, nonprofit, group practice.”

Source: RevenueBase Database · checked Sep 20, 2026
2Indirect evidencePleasanton, CA, United StatesHQ checked Sep 20, 202610001+3,258 contacts →

Indirect evidence

“The Permanente Medical Group (TPMG) is the largest physician-led medical group in the United States.”

Source: RevenueBase Database · checked Sep 20, 2026
3Partial evidenceNewton, MA, United StatesHQ checked Sep 20, 20265,001-10,0001,906 contacts →

Partial evidence

“Atrius Health, an innovative healthcare leader, delivers an effective system of connected care for adult and pediatric patients at 30 medical practice locations in eastern…”

Source: RevenueBase Database · checked Sep 20, 2026
4Indirect evidenceDowners Grove, IL, United StatesHQ checked Sep 20, 20261,001-5,0001,438 contacts →

Indirect evidence

“Are you ready to challenge the expected to deliver the extraordinary?”

Source: RevenueBase Database · checked Sep 20, 2026
5Indirect evidenceAnn Arbor, MI, United StatesHQ checked Sep 20, 20261,001-5,0001,339 contacts →

Indirect evidence

“Established in 1994, Trinity Health IHA Medical Group is one of the largest multi-specialty medical groups in Michigan delivering more than one million patient visits each year…”

Source: RevenueBase Database · checked Sep 20, 2026
6Partial evidenceHattiesburg, MS, United StatesHQ checked Sep 20, 20261,001-5,000932 contacts →

Partial evidence

“Hattiesburg Clinic’s mission as a group practice is to provide high quality, patient-centered health care in an efficient and cost-effective manner.”

Source: RevenueBase Database · checked Sep 20, 2026
7Indirect evidenceLos Angeles, CA, United StatesHQ checked Sep 20, 20261,001-5,000840 contacts →

Indirect evidence

“Regal Medical Group, Lakeside Community Healthcare, ADOC Medical Group, and Community Surgery Center of Glendale – part of the Heritage Provider Network – is recognized as one of…”

Source: RevenueBase Database · checked Sep 20, 2026
8Indirect evidenceMiddletown, NY, United StatesHQ checked Sep 20, 20261,001-5,000771 contacts →

Indirect evidence

“We’re redefining & transforming the approach to health, the business of health, & the overall well-being of the community.”

Source: RevenueBase Database · checked Sep 20, 2026
9Indirect evidenceToledo, OH, United StatesHQ checked Sep 20, 20261,001-5,000546 contacts →

Indirect evidence

“A large private multi-specialty physician group in the city of Toledo.”

Source: RevenueBase Database · checked Sep 20, 2026
10Partial evidencePortland, ME, United StatesHQ checked Sep 20, 2026501-1,000455 contacts →

Partial evidence

“InterMed is the largest physician-owned primary care practice in Maine, with 90 physicians and more than 650 non-physician employees.”

Source: RevenueBase Database · checked Sep 20, 2026
11Partial evidenceWest Orange, NJ, United StatesHQ checked Sep 20, 2026501-1,000406 contacts →

Partial evidence

“RWJBarnabas Health Medical Group is a multi-specialty group practice comprised of highly trained and experienced world class primary and specialty care physicians.”

Source: RevenueBase Database · checked Sep 20, 2026
12Indirect evidenceBuffalo, NY, United StatesHQ checked Sep 20, 2026501-1,000386 contacts →

Indirect evidence

“At Buffalo Medical Group, we offer care that goes beyond simply treating you when you’re sick.”

Source: RevenueBase Database · checked Sep 20, 2026
13Indirect evidenceThe Villages, FL, United StatesHQ checked Sep 20, 2026501-1,000349 contacts →

Indirect evidence

“The Villages Health (soon becoming CenterWell Senior Primary Care) offers a revolutionary style of care that puts the patient at the center of their own well being!”

Source: RevenueBase Database · checked Sep 20, 2026
14Indirect evidenceDurham, NC, United StatesHQ checked Sep 20, 202610001+335 contacts →

Indirect evidence

“Visit our main page: Duke University Health System”

Source: RevenueBase Database · checked Sep 20, 2026
15Indirect evidenceLeesburg, VA, United StatesHQ checked Sep 20, 20261,001-5,000318 contacts →

Indirect evidence

“Our goal at Loudoun Medical Group (LMG) is to provide every single patient with top-quality medical care and personalized service.”

Source: RevenueBase Database · checked Sep 20, 2026
16Indirect evidenceGainesville, GA, United StatesHQ checked Sep 20, 2026501-1,000312 contacts →

Indirect evidence

“Longstreet Clinic is a leading-edge, private medical group located in north Georgia.”

Source: RevenueBase Database · checked Sep 20, 2026
17Indirect evidenceHigh Point, NC, United StatesHQ checked Sep 20, 2026201-500276 contacts →

Indirect evidence

“At Bethany Medical, Your Health is Our Concern!”

Source: RevenueBase Database · checked Sep 20, 2026
18Partial evidenceProvidence, RI, United StatesHQ checked Sep 20, 2026501-1,000256 contacts →

Partial evidence

“A member of the Lifespan health system, Coastal Medical is a primary care driven practice serving over patients with a team of 150 clinicians located in medical offices across…”

Source: RevenueBase Database · checked Sep 20, 2026
19Partial evidenceTucson, AZ, United StatesHQ checked Sep 20, 2026501-1,000242 contacts →

Partial evidence

“Arizona Community Physicians is the largest physician owned medical practice in the state of Arizona, with 130 physicians and a total of 35 Physician Assistants and Nurse…”

Source: RevenueBase Database · checked Sep 20, 2026
20Indirect evidenceSan Antonio, TX, United StatesHQ checked Sep 20, 2026201-500235 contacts →

Indirect evidence

“Texas MedClinic Urgent Care is now CareNow Urgent Care/HCA Healthcare.”

Source: RevenueBase Database · checked Sep 20, 2026
21Indirect evidenceAntioch, CA, United StatesHQ checked Sep 20, 2026201-500230 contacts →

Indirect evidence

“Founded in the 1990’s, Epic Care started as a group of board certified hematologists and oncologists based in Northern California’s East Bay area.”

Source: RevenueBase Database · checked Sep 20, 2026
22Strong evidenceCheyenne, WY, United StatesHQ checked Sep 20, 202651-200227 contacts →

Strong evidence

“Specialist focused Multi-Specialist Internal Medicine Group located in Cheyenne, WY.”

Source: RevenueBase Database · checked Sep 20, 2026
23Indirect evidencePhoenix, AZ, United StatesHQ checked Sep 20, 2026501-1,000223 contacts →

Indirect evidence

“IMS Care Center is a physician-led organization united through its providers’ commitment to high-quality, innovative health care.”

Source: RevenueBase Database · checked Sep 20, 2026
24Indirect evidenceHixson, TN, United StatesHQ checked Sep 20, 2026501-1,000218 contacts →

Indirect evidence

“Galen Medical Group was founded in October 1992, as a multispecialty medical group to meet the goals set forth in its Mission Statement.”

Source: RevenueBase Database · checked Sep 20, 2026
25Indirect evidencePoughkeepsie, NY, United StatesHQ checked Sep 20, 2026501-1,000209 contacts →

Indirect evidence

“We provide patients with in-depth and compassionate care to treat the whole you in the fields of urology, gynecology, gastroenterology, rheumatology, cardiology, dermatology…”

Source: RevenueBase Database · checked Sep 20, 2026

Showing 25 of 3,469 internal medicine practices based in the United States

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Internal medicine practices based in the United States at a glance

As of Sep 20, 2026
22.0%Verified-email coverage
14.1Average contacts per company
1-10Median size (employees)
2.6%Largest-city concentration · New York
Sep 20, 2026Page data refreshed

Companies by employee count

1-10
1,933
11-50
1,132
51-200
251
201-500
65
501-1,000
23
1,001-5,000
18
5,001-10,000
5
10001+
4

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 3,469 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among internal medicine practices, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “internal medicine practices”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names internal medicine practices), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among internal medicine practices, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 10,788 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 20, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Internal medicine practices by metro

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names internal medicine practices, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many internal medicine practices are there based in the United States?

RevenueBase identified 3,469 internal medicine practices headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Lahey Hospital & Medical Center, headquartered in Burlington, tops this list with the largest team on record.

Which city has the most internal medicine practices?

New York leads with 91 headquartered companies, followed by Houston (51) and Miami (31).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 10,788 verified decision-maker contacts tracked across these 3,469 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 20, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.