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DR. MARK E WILLIAMS MD
NPI 1184653891
Internal Medicine - Nephrology in Boston, MA

Active since July 03, 2006PECOS EnrolledAccepts Medicare Assignment
1 JOSLIN PL, BOSTON, MA 02215(617) 732-2477(617) 732-2467 Get Directions Write a Review

NPPES record last updated: April 25, 2011. Verified against the NPPES registry weekly; last sync: August 02, 2026.

About Dr. Mark E Williams Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. MARK E WILLIAMS MD (NPI 1184653891) is an individual nephrology provider in Boston, Massachusetts, licensed in Massachusetts (45103) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS, is affiliated with Beth Israel Deaconess Medical Center, and is a graduate of Indiana University School Of Medicine (1977).

NPPES Registry Identity

NPI1184653891
Entity TypeIndividualMale
Primary Taxonomy207RN0300X
Provider Legal NameDR. MARK E WILLIAMSCredential: MD
Location Address1 JOSLIN PLBoston, MA 02215-5306
Mailing Address31 Hereford StBoston, MA 02115-1718 · (617) 267-5652 · Fax (617) 735-1916
Phone(617) 732-2477
Fax(617) 732-2467
Sole ProprietorNo
Medical School CMSIndiana University School Of MedicineGraduated 1977
Enumeration DateJuly 3, 2006
Last NPPES UpdateApril 25, 2011
✔ NPI 1184653891 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · NephrologyAllopathic & Osteopathic Physicians
Taxonomy Code207RN0300X
License✔ Licensed in MA · 45103
Definition
An internist who treats disorders of the kidney, high blood pressure, fluid and mineral balance and dialysis of body wastes when the kidneys do not function. This specialist consults with surgeons about kidney transplantation.
Also ListedSpecialistTaxonomy 174400000X · License 45103 (MA)
1 JOSLIN PL, Boston, MA 02215
Open in Google Maps ↗

Other Identifiers 3

Medicare ID-Type UnspecifiedE05276
Medicare UPINC46385MA
Medicaid0112542MA

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Mark E Williams Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID2062443070
PECOS Enrollment IDI20050829000815, I20250808004060
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 9

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Hemodialysis procedure with physician evaluation 90935
Hemodialysis is a treatment that uses a machine to filter waste and excess fluid from your blood when your kidneys can't. A physician checks your health before, during, and after the procedure to ensure it's working effectively for you.
281 services87 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
127 services79 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
104 services38 patients
Dialysis services, 4 or more physician visits per month (20 years or older) 90960
Dialysis is a treatment that filters and purifies your blood using a machine. It helps keep your fluids and electrolytes in balance when the kidneys can't do their job. This service includes 4 or more visits per month with a physician to monitor your health and adjust your treatment as needed.
73 services18 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
73 services61 patients
Dialysis procedure including 1 evaluation 90945
Dialysis is a treatment that filters and purifies the blood when your kidneys can't do their job. The procedure involves circulating your blood through a machine that removes waste products. An evaluation is done beforehand to assess your health and determine the best approach for your treatment.
46 services14 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Beth Israel Deaconess Medical Center

Acute Care Hospitals · Boston, MA
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220086
Location330 Brookline AvenueBoston, MA 02215 · Suffolk County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02215 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$144.11 typical visit price
range $63.72 – $189.86
Typical copayment $36.02 (range $15.93 – $47.46)
Most-billed visit code 99204
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims 4

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Tacrolimus, immediate release, oral, 1 mg J7507
Treatment-Treatment - Miscellaneous · category RX029N
2 suppliers17 claims3,120 services$0.34 avg. paid by Medicare
Mycophenolate mofetil, oral, 250 mg J7517
Treatment-Treatment - Miscellaneous · category RX029N
1 supplier12 claims1,440 services$0.20 avg. paid by Medicare
Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for the first prescription in a 30-day period Q0511
Treatment-Chemotherapy · category RH012N
2 suppliers16 claims16 services$18.97 avg. paid by Medicare
Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for a subsequent prescription in a 30-day period Q0512
Treatment-Chemotherapy · category RH012N
2 suppliers13 claims13 services$12.64 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. EDWARD SCHURR HORTON M.D.
Internal Medicine (Endocrinology, Diabetes & Metabolism)
1 JOSLIN PL
BOSTON, MA 02215
Suffolk County (617) 309-2400
MS. LOUISE AMBLER OSBORN CPNP
Nurse Practitioner (Pediatrics)
1 JOSLIN PL
BOSTON, MA 02215
Suffolk County (617) 732-2603
DR. JASON L GAGLIA M.D.
Internal Medicine (Endocrinology, Diabetes & Metabolism)
1 JOSLIN PL, ROOM 470
BOSTON, MA 02215
Suffolk County (617) 732-2675
KARA ROMAN HARRINGTON PHD
Psychologist
1 JOSLIN PL, DEPARTMENT OF PEDIATRICS
BOSTON, MA 02215
Suffolk County (617) 732-2603
CATERINA MORGERA MS, RD, LDN, CDOE
Dietitian, Registered
1 JOSLIN PL
BOSTON, MA 02215
Suffolk County (617) 309-2440
MR. JOYCE KEADY PNP, RN
Nurse Practitioner (Pediatrics)
1 JOSLIN PL
BOSTON, MA 02215
Suffolk County (617) 309-4499
DR. JASON NOBLE M.D.
Ophthalmology
1 JOSLIN PL
BOSTON, MA 02215
Suffolk County (617) 732-2586
ASSEL TALASPAYEVA MD
Ophthalmology
1 JOSLIN PL
BOSTON, MA 02215
Suffolk County (617) 309-2400

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Mark Williams's NPI number?

The NPI number for Mark Williams is 1184653891. It was assigned to this individual provider in the NPPES registry on July 3, 2006.

Where is Mark Williams located?

Mark Williams practices at 1 Joslin Pl, Boston, MA 02215. The listed phone number is (617) 732-2477.

What is Mark Williams's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Nephrology, with taxonomy code 207RN0300X.

Is Mark Williams enrolled in Medicare?

Yes. Mark Williams is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

What insurance does Mark Williams accept?

Health plans from Anthem Blue Cross and Blue Shield list Mark Williams as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Mark Williams affiliated with any hospitals?

According to CMS data, Mark Williams is affiliated with Beth Israel Deaconess Medical Center.

When was this NPI record last updated?

The NPPES record for Mark Williams was last updated on April 25, 2011. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.