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LINUS CLARK WILLIAMS MD, PHD
NPI 1811671522
Internal Medicine in Burlington, MA

Active since June 13, 2023PECOS EnrolledAccepts Medicare Assignment
67 S BEDFORD ST STE 202, BURLINGTON, MA 01803(781) 744-7000 Get Directions Write a Review

NPPES record last updated: August 3, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Aug 3, 2026, Jun 13, 2023 (2 updates tracked since 2023).

About Linus Clark Williams Md, Phd NPPES

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

LINUS CLARK WILLIAMS MD, PHD (NPI 1811671522) is an individual internal medicine provider in Burlington, Massachusetts, licensed in Massachusetts (3015290) and active in the NPI registry since June 2023. He is enrolled in Medicare PECOS, maintains a secondary practice location in Burlington, and is a graduate of Other (2021).

NPPES Registry Identity

NPI1811671522
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameLINUS CLARK WILLIAMSCredential: MD, PHD
Location Address67 S BEDFORD ST STE 202Burlington, MA 01803-5108
Mailing Address67 S Bedford St Ste 202Burlington, MA 01803-5108 · (781) 744-7000
Phone(781) 744-7000
Sole ProprietorYes
Medical School CMSOtherGraduated 2021
Enumeration DateJune 13, 2023
Last NPPES UpdateAugust 3, 20262 updates tracked since enumeration
NPPES CertifiedAugust 3, 2026
✔ NPI 1811671522 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in MA · 3015290
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
67 S BEDFORD ST STE 202, Burlington, MA 01803
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Secondary Practice Location 1

Location 141 Mall RdBurlington, MA 01805-0001 · Phone (781) 744-5100

Group Practice 1

Group TaxonomyThis provider is a business group of one or more individual practitioners, who practice with different areas of specialization.193200000X MULTI-SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Linus Clark Williams Md, Phd 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 ID3476010679
PECOS Enrollment IDI20260807000632
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.

Medicare Billing Reassignment

Medicare enrollment records show Linus Williams reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Lahey Clinic, Inc.
1.2 mi
Internal Medicine
41 MALL RD, LAHEY CLINIC
Burlington, MA 01805
  • Reassigned Medicare billing, Massachusetts enrollment
  • 1,574 clinicians in this Medicare group
NPI 1538194980 (781) 744-8000

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 01803 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.

Other Providers at the Same Location NPPES

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

MRS. MELANIE MARIE CRONIN RN
Nurse Practitioner (Family)
67 S BEDFORD ST STE 202
BURLINGTON, MA 01803
Middlesex County (781) 744-7000

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 Linus Williams's NPI number?

The NPI number for Linus Williams is 1811671522. It was assigned to this individual provider in the NPPES registry on June 13, 2023.

Where is Linus Williams located?

Linus Williams practices at 67 S Bedford St Ste 202, Burlington, MA 01803. The listed phone number is (781) 744-7000.

What is Linus Williams's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Linus Williams enrolled in Medicare?

Yes. Linus 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.

Which organization bills Medicare for Linus Williams's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Linus Williams reassigns Medicare benefits to Lahey Clinic, Inc. (Burlington, MA). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Linus Williams's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Linus Williams was last updated on August 3, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 months 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.