2026 NPPES data Family Medicine Physician NPI 1134107436 M.D.
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CHARLES WILLIAMS, M.D.

Family Medicine Physician in EAST BOSTON, Massachusetts. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
288
Medicare Part D claims · 45 beneficiaries · Family Medicine Physician avg: 3K
Generic prescribing
80%
generic claims · 20% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

CHARLES WILLIAMS, M.D. filed 288 Medicare Part D claims in 2023 as a Family Medicine Physician in EAST BOSTON, Massachusetts, prescribing 80% generic.

288
Part D claims, 2023
80%
generic prescribing
Likely
board-certified (heuristic)

Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.

CHARLES WILLIAMS, M.D.'s Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

288 49th percentile higher than 49% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source CMS Medicare Part D Prescriber Public Use File · 2023

Board certification likely (heuristic — not verified)

CHARLES WILLIAMS, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about CHARLES WILLIAMS, M.D.?

Quality data not reported

NPI registry status

Active

Issued 01/06/2006

NPI 1134107436

Primary specialty

Family Medicine Physician

High-volume

147,640 US NPIs in this specialty

Medicare Part D claims

288 92% vs specialty avg

2023 prescription claims

Specialty avg: 3,418

Specialty distribution in Massachusetts

How Family Medicine Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Family Medicine Physician share within Massachusetts

1. Family Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Family Medicine Physician share within Massachusetts

Specialty board-certification context

Estimated specialty board-certified rate — Family Medicine Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Family Medicine Physician ABMS/AOA estimate

Est. board-certified rate (Family Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Family Medicine Physician) — ABMS / AOA estimate

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

CHARLES WILLIAMS, M.D. appears in the CMS NPPES registry as a Family Medicine Physician provider holding M.D. credentials at 10 GOVE ST, EAST BOSTON, MA, 02128, with a listed phone of (617) 569-5800. NPI 1134107436 was issued on 01/06/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what WILLIAMS most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 288 prescription claims written by this provider, covering 45 Medicare beneficiaries and totaling roughly $44K in drug spend, split 20% brand-name and 80% generic by claim count, with an opioid prescribing rate of 16.3%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Family Medicine Physician is a high-volume specialty nationwide, with 147,640 enrolled providers across 56 states and an average of 3,418 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

10 GOVE ST
EAST BOSTON, MA 02128

Provider Details

NPI 1134107436
Specialty Family Medicine Physician
Credentials M.D.
Gender Male
NPI Issued 01/06/2006

Hospital and facility affiliations

Facilities where CHARLES WILLIAMS, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

INTERNAL MEDICAL ASSOCIATES-EBNHC
EAST BOSTON, MA

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

License & disciplinary context — Massachusetts BORIM 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~38K Massachusetts medical licensees in 2023 — they are NOT specific to CHARLES WILLIAMS, M.D.. To verify CHARLES WILLIAMS, M.D.'s current license status, search the BORIM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

80
Total board actions, Massachusetts 2023
Across 78 cases
2.11
Actions per 1,000 licensees
Massachusetts statewide rate
probation
Most common action type
29 cases

BORIM publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Massachusetts disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

CHARLES WILLIAMS, M.D. — brand share 20.0%
Specialty average (est.)

20% brand-name claims vs 80% generic, on 288 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

288
Total Claims
$44K
Total Drug Cost
45
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
511
Total Day Supply
14,421
Brand vs Generic
20% brand / 80% generic
Brand Drug Cost
$40K
Generic Drug Cost
$5K
Opioid Claims
47 (16.3% rate)

Patient Demographics

Average Patient Age
69.6 years
Avg HCC Risk Score
1.43
Gender Split
27% female / 73% male

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What CHARLES WILLIAMS, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Oxycodone Hcl
37
Trulicity
Dulaglutide
22
Lisinopril
13

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Family Medicine Physician Overview

How CHARLES WILLIAMS, M.D. fits within the Family Medicine Physician landscape nationally.

147,640
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider

CHARLES WILLIAMS, M.D.'s 288 claims are below the specialty average of 3,418.

Nearby Family Medicine Physician Providers in Massachusetts

Other clinicians with the same primary specialty enrolled in Massachusetts, drawn from the same CMS NPPES roster as WILLIAMS.

Compare Family Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is CHARLES WILLIAMS, M.D.'s specialty?
CHARLES WILLIAMS, M.D. specializes in Family Medicine Physician and practices in EAST BOSTON, Massachusetts. Credentials: M.D..
How much does CHARLES WILLIAMS, M.D. prescribe under Medicare Part D?
In 2023, CHARLES WILLIAMS, M.D. wrote 288 Medicare Part D claims totaling $44K in drug costs for 45 beneficiaries.
Where is CHARLES WILLIAMS, M.D. located?
CHARLES WILLIAMS, M.D. is located at 10 GOVE ST, EAST BOSTON, MA, 02128. Phone: (617) 569-5800.
What is CHARLES WILLIAMS, M.D.'s NPI number?
CHARLES WILLIAMS, M.D.'s National Provider Identifier (NPI) is 1134107436, issued on 01/06/2006.
Does CHARLES WILLIAMS, M.D. prescribe more brand-name or generic drugs?
CHARLES WILLIAMS, M.D.'s prescribing is 20% brand-name and 80% generic drugs by claim count, with $40K in brand drug costs.
Does CHARLES WILLIAMS, M.D. prescribe opioids?
Yes, CHARLES WILLIAMS, M.D. had 47 opioid claims in 2023 with an opioid prescribing rate of 16.3%.
How many Family Medicine Physician providers are there in the US?
There are 147,640 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does CHARLES WILLIAMS, M.D. prescribe most often?
Based on 2023 Medicare Part D data, CHARLES WILLIAMS, M.D.'s most frequently prescribed drugs include Oxycodone Hcl, Trulicity, Lisinopril. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CHARLES WILLIAMS, M.D. accept Medicare?
CHARLES WILLIAMS, M.D. appears in CMS Medicare data with 288 Part D claims and 45 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CHARLES WILLIAMS, M.D.'s credentials?
CHARLES WILLIAMS, M.D.'s NPI is 1134107436 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology