Dr. Mark J. Sarnak, MD
- Medicare services, 2024
- 435
- Medicare patients, 2024
- 154
- Part D claims, 2024
- 11
- Hospital affiliations
- 1
- Industry payments
- $11,567
- Practice address
- 800 Washington Street, Boston, MA 02111
- Practice phone
- Call (617) 636-5000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Sarnak's professional email, personal email and mobile number
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Dr. Mark J. Sarnak is a nephrologist in Boston, Massachusetts
Dr. Sarnak practices at Tufts Medical Center in Boston, Massachusetts, part of Tufts Medicine.
Dr. Sarnak's NPI, 1982641502, was assigned on June 1, 2006. Dr. Sarnak graduated from Columbia University College of Physicians and Surgeons in 1993. Dr. Sarnak holds Massachusetts license 82001.
- NPI
- 1982641502NPI Registry (opens in a new tab)
- Medicare PAC ID
- 7618169434
- NPI enumeration date
- June 1, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (617) 636-5000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 59
- Medical school graduation
- 1993
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Mark J. Sarnak practices at Tufts Medical Center in Boston, Massachusetts
Dr. Sarnak's primary practice is Tufts Medical Center, at 800 Washington Street, Boston, MA 02111 in Suffolk County. The practice phone is (617) 636-5000.
- Tufts Medical Center800 Washington Street, Boston, MA 02111 · Suffolk CountyPhone(617) 636-5000
Source: Dmand AI Affiliation Data
Dr. Mark J. Sarnak is affiliated with 2 sites of care and 1 medical group
Dr. Sarnak's primary practice is Tufts Medical Center in Boston, Massachusetts, part of Tufts Medicine. The medical group on file is Pratt Medical Group, Inc. - General Medical Associates (General Internal Medicine). Dmand AI also links Dr. Sarnak to 1 more imaging center, named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Mark J. Sarnak's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Sarnak practices, 2 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Tufts Medical Center | Available with a free account |
| +1 more affiliated site | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across Tufts Medicine and 6.2K+ hospitals, with verified contacts in the same login.
Dr. Mark J. Sarnak is one of 351 nephrologists in Massachusetts
Nephrology is Dr. Sarnak's primary specialty in the NPI Registry, under taxonomy code 207RN0300X. Dr. Sarnak is licensed in Massachusetts.
Specialties and state licenses
- Nephrology, MassachusettsPrimary
Nephrologists near Dr. Sarnak
Counts of nephrologists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Mark J. Sarnak billed Medicare for 435 services in 2024
CMS data shows 435 Medicare services from Dr. Sarnak across 6 procedure codes in 2024, for 154 Medicare patients. Medicare paid $28,686 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Sarnak's Medicare services by type, 2024
- Office and hospital visits338
- Other services97
Dr. Sarnak compared with the Massachusetts median for nephrologists, 2024
- Dr. Sarnak
- Massachusetts median
- Medicare services
- 435vs 70138% below
- Medicare patients
- 154vs 28245% below
Medians across 333 nephrologists in Massachusetts with Dmand AI profiles that report each measure.
Dr. Sarnak's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Sarnak and other nephrologists in Massachusetts.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Mark J. Sarnak treated 154 Medicare patients in 2024, average age 71
CMS counts 154 Medicare patients who saw Dr. Sarnak in 2024. The largest group is 65 to 74, with 64 patients. 75% of them have chronic kidney disease, and 75% have high blood pressure. 42% are also on Medicaid. Their average risk score is 4.28, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Sarnak's median patient age at 64, with 41% women.
Dr. Sarnak's Medicare patients by age, 2024
Dr. Sarnak's Medicare patients by sex, 2024
- Women6542%
- Men8958%
Chronic conditions among Dr. Sarnak's Medicare patients, 2024
- Chronic kidney disease75%
- High blood pressure75%
- High cholesterol75%
- Heart failure51%
- Ischemic heart disease51%
- Diabetes50%
- Arthritis45%
- Anxiety41%
Share of Medicare patients with each condition. A patient can have several.
Dr. Sarnak's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 64
Patient panel by sex, all payers
- Women41%
- Men59%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Mark J. Sarnak wrote 11 Medicare Part D claims in 2024
In 2024, Dr. Sarnak wrote 11 Medicare Part D claims.
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Mark J. Sarnak takes part in Medicare
Dr. Sarnak accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Mark J. Sarnak received $11,567 in industry payments from 2024 to 2025
CMS Open Payments shows 16 general payments to Dr. Sarnak from 3 drug and device companies from 2024 to 2025. Consulting fees make up the largest share, 100% of the total. AstraZeneca Pharmaceuticals LP paid the most, $7,000.
General payments to Dr. Sarnak by program year, 2024 to 2025
General payments to Dr. Sarnak by kind, 2024 to 2025
- Consulting fees$11,535100%
- Education$320%
Companies that paid Dr. Sarnak the most, 2024 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Mark J. Sarnak graduated from Columbia University College of Physicians and Surgeons
Dr. Sarnak graduated from Columbia University College of Physicians and Surgeons in 1993.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Mark J. Sarnak's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Mark J. Sarnak
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Mark J. Sarnak's NPI number?
Dr. Mark J. Sarnak's NPI number is 1982641502. It was assigned on June 1, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Mark J. Sarnak?
Dr. Mark J. Sarnak is a nephrologist in Boston, Massachusetts. The primary specialty in the NPI Registry is Nephrology Physician (taxonomy code 207RN0300X).
Where does Dr. Mark J. Sarnak practice?
Dr. Sarnak practices at 800 Washington Street, Boston, MA 02111. Dr. Sarnak's primary practice is Tufts Medical Center in Boston, Massachusetts, part of Tufts Medicine. Dmand AI also links Dr. Sarnak to 1 imaging center.
What is Dr. Mark J. Sarnak's office phone number?
The practice phone on file for Dr. Sarnak is (617) 636-5000.
What is Dr. Mark J. Sarnak's medical license number?
Dr. Sarnak holds Massachusetts license 82001.
Which hospitals is Dr. Mark J. Sarnak affiliated with?
Dr. Sarnak practices at Tufts Medical Center in Boston, Massachusetts.
What medical group is Dr. Mark J. Sarnak part of?
Dr. Sarnak is linked to Pratt Medical Group, Inc. - General Medical Associates (General Internal Medicine).
Does Dr. Mark J. Sarnak accept Medicare?
Yes. CMS data shows Dr. Sarnak billed Medicare for 435 services in 2024, and Dr. Sarnak accepts Medicare assignment.
How many Medicare patients does Dr. Mark J. Sarnak see?
CMS counts 154 Medicare patients who saw Dr. Sarnak in 2024, with an average age of 71.
What services does Dr. Mark J. Sarnak bill to Medicare?
In 2024, Dr. Sarnak's most billed Medicare services were hospital inpatient care (99232), office visit, established patient (99214) and medicare service (G2211).
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Where did Dr. Mark J. Sarnak go to medical school?
Dr. Sarnak graduated from Columbia University College of Physicians and Surgeons in 1993.
Has Dr. Mark J. Sarnak received payments from drug or device companies?
CMS Open Payments shows $11,567 in general payments to Dr. Sarnak from 3 companies from 2024 to 2025. The largest total came from AstraZeneca Pharmaceuticals LP.
How long has Dr. Mark J. Sarnak been practicing?
Dr. Sarnak graduated from medical school in 1993, 33 years ago.
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