Medical Specialty Listing

Internal Medicine Providers in Waltham, MA

Browse 32 Internal Medicine providers listed in NPPES with a practice address in Waltham, Massachusetts.

32 Healthcare Providers

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How Waltham compares with the U.S.

Waltham has 49 clinicians in Internal Medicine per 100,000 residents, 11% higher than the U.S. rate of 44.

That is 32 active clinicians in Internal Medicine with a practice address in Waltham, for a population of 64,902.

The Massachusetts rate is 97 per 100,000 residents.

What these numbers mean

Clinicians per 100,000 residents compares places of different sizes. We count active clinicians who list a practice address in the area in the federal NPI registry (NPPES) and divide by the number of people who live there, according to the U.S. Census Bureau. The U.S. rate is the same calculation for the whole country.

A higher number does not mean it is easier to get an appointment, that wait times are shorter, or that care is better. It also does not show how many clinicians are accepting new patients or which insurance plans they take. A lower number does not by itself mean there is a shortage.

City counts use the city name in each clinician's practice address. That postal city can cover a larger or smaller area than the city limits the Census Bureau uses for population, and many clinicians list only one address even if they work in several places.

94% of clinicians in Internal Medicine in Waltham listed in the CMS Medicare file (15 of 16) accept Medicare assignment. That is similar to the Massachusetts share of 96%.

What is Medicare assignment?

A clinician who accepts Medicare assignment agrees to take the Medicare-approved amount as full payment for services that Original Medicare covers. You usually still pay your deductible and coinsurance. This comes from the CMS Doctors and Clinicians file and applies to Original Medicare only. Medicare Advantage plans have their own provider networks. It does not show whether a clinician is taking new patients.

Some clinicians are listed as "may accept assignment," which means they can decide case by case. Clinicians without an assignment flag, or who are not in the CMS file, are not counted as accepting assignment. That does not mean they refuse Medicare. Ask the office before your visit.

63% of clinicians in Internal Medicine in Waltham listed in the CMS Medicare file (10 of 16) have a CMS telehealth indicator, meaning their recent Medicare claims include telehealth services. That is higher than the Massachusetts share of 48%.

About the telehealth indicator

The telehealth indicator comes from CMS. It marks clinicians whose recent paid Medicare claims include services delivered by telehealth. It means a clinician has provided some services by telehealth, not that every visit can be done online. A clinician without the indicator may still offer telehealth, for example to patients who are not on Medicare. Ask the office which visits can be done by video or phone.

These figures summarize public federal data. They do not measure quality of care, appointment availability, or whether a clinician accepts your insurance or new patients. Registry addresses can be out of date. Please confirm details directly with the office and your plan. This information is not medical advice.

Prepared by T-MedInfo from NPPES, CMS and U.S. Census Bureau data. Questions or corrections: support@true-medinfo.com · Methodology

Sources: Clinician counts and practice addresses: NPPES NPI Registry, Centers for Medicare & Medicaid Services (CMS), data as of August 2026. Medicare assignment and telehealth indicators: CMS Doctors and Clinicians National Downloadable File. Population: U.S. Census Bureau, American Community Survey 2020-2024 5-Year Estimates, Table B01003 (Total Population).

Internal Medicine Medicare (PECOS) Enrollment & Ordering Eligibility

Medicare enrollment and order/referring eligibility listed by CMS for Internal Medicine practitioners in Waltham, MA

Source: CMS PECOS

PECOS Enrolled Specialists 20 In Waltham, MA

Part B Lab & Imaging Eligible 20 Diagnostic Referrals

DME Ordering Eligible 21 Durable Medical Equipment

Home Health Agency Referrals 20 HHA Ordering Eligible

Showing 1–20 of 32 providers

With recent CMS data first, then A–Z

Dr. Rachel Ackerman , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available

355 Waverly Oaks Rd Ste 200, Waltham, MA 02452

Phone: 7816476920

NPI Identifier 1376923094

Internal Medicine Providers in Waltham, MA

How Waltham compares with the U.S.

Internal Medicine Medicare (PECOS) Enrollment & Ordering Eligibility

Dr. Rachel Ackerman , MD

Dr. Devasena Balasubramaniam , MD

Dr. Edward James Busick , MD

Dr. Mark Robert Drews , MD

Dr. Barry A Ehrlich , MD

Dr. Thomas A Fry , MD

Dr. Christina Gelev , MD

Dr. Brittany Michelle Hansen , MD

Dr. Daniel M Horn , MD

Dr. Steven R Kanner , MD

Dr. Wissam J Khoory , MD

Dr. Monica Manandhar , MD

Dr. Allison Lloyd Mcdonough , MD

Dr. Henry John Merola , MD

Dr. Julie Pfeffer , MD

Dr. Joanna Ellen Schwartz , MD

Dr. Elissa Stecker , MD

Dr. Hadia Fatima Tirmizi , MD

Dr. Leslie A Vensel , MD

Dr. Alice L Zacarian , MD

Frequently Asked Questions about Internal Medicine in Waltham

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