2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1659434421
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MICHAEL FREEMARK

Endocrinology, Diabetes & Metabolism Physician in DURHAM, North Carolina. 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
49
Medicare Part D claims · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
43%
generic claims · 57% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: MICHAEL FREEMARK is a Endocrinology, Diabetes & Metabolism Physician ([object Object]) practicing in DURHAM, North Carolina with a Medicare Part D prescribing footprint of 49 claims — 57% brand-name prescribing .

What stands out: MICHAEL FREEMARK filed 49 Medicare Part D claims in 2023 across DURHAM, North Carolina. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

MICHAEL FREEMARK practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).

MICHAEL FREEMARK at a glance

Quality data not reported

NPI registry status

Active

Issued 12/19/2006

NPI 1659434421

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

49 98% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

Specialty distribution in North Carolina

How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among North Carolina providers

North Carolina providers

Endocrinology, Diabetes & Metabolism Physician share within North Carolina

1. Endocrinology, Diabetes & Metabolism Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Endocrinology, Diabetes & Metabolism Physician share within North Carolina

Specialty board-certification context

Estimated specialty board-certified rate — Endocrinology, Diabetes & Metabolism Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Endocrinology, Diabetes & Metabolism Physician ABMS/AOA estimate

Est. board-certified rate (Endocrinology, Diabetes & Metabolism Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Endocrinology, Diabetes & Metabolism 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).

MICHAEL FREEMARK is a Endocrinology, Diabetes & Metabolism Physician provider practicing in DURHAM, North Carolina, according to the CMS National Plan and Provider Enumeration System (NPPES). NPI: 1659434421. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

MICHAEL FREEMARK appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider at 2100 ERWIN RD, DURHAM, NC, 27710, with a listed phone of (919) 684-8111. NPI 1659434421 was issued on 12/19/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FREEMARK 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 49 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $29K in drug spend, split 57% brand-name and 43% generic by claim count. 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.

Endocrinology, Diabetes & Metabolism Physician is a mid-sized specialty nationwide, with 7,852 enrolled providers across 54 states and an average of 2,639 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

2100 ERWIN RD
DURHAM, NC 27710

Provider Details

NPI 1659434421
Specialty Endocrinology, Diabetes & Metabolism Physician
Gender Male
NPI Issued 12/19/2006

Brand vs generic prescribing mix · Brand-heavy

MICHAEL FREEMARK — brand share 57.0%
Specialty average (est.)

57% brand-name claims vs 43% generic, on 49 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.

49
Total Claims
$29K
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
100
Total Day Supply
2,894
Brand vs Generic
57% brand / 43% generic
Brand Drug Cost
$28K

Patient Demographics

Average Patient Age
29.1 years
Avg HCC Risk Score
2.35

Endocrinology, Diabetes & Metabolism Physician Overview

How MICHAEL FREEMARK fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.

7,852
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,639
Avg Claims per Provider

MICHAEL FREEMARK's 49 claims are below the specialty average of 2,639.

Nearby Endocrinology, Diabetes & Metabolism Physician Providers in North Carolina

Other clinicians with the same primary specialty enrolled in North Carolina, drawn from the same CMS NPPES roster as FREEMARK.

Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is MICHAEL FREEMARK's specialty?
MICHAEL FREEMARK specializes in Endocrinology, Diabetes & Metabolism Physician and practices in DURHAM, North Carolina.
How much does MICHAEL FREEMARK prescribe under Medicare Part D?
In 2023, MICHAEL FREEMARK wrote 49 Medicare Part D claims totaling $29K in drug costs for N/A beneficiaries.
Where is MICHAEL FREEMARK located?
MICHAEL FREEMARK is located at 2100 ERWIN RD, DURHAM, NC, 27710. Phone: (919) 684-8111.
What is MICHAEL FREEMARK's NPI number?
MICHAEL FREEMARK's National Provider Identifier (NPI) is 1659434421, issued on 12/19/2006.
Does MICHAEL FREEMARK prescribe more brand-name or generic drugs?
MICHAEL FREEMARK's prescribing is 57% brand-name and 43% generic drugs by claim count, with $28K in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US?
There are 7,852 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,639 Medicare Part D claims per year.
Does MICHAEL FREEMARK accept Medicare?
MICHAEL FREEMARK appears in CMS Medicare data with 49 Part D claims and N/A Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MICHAEL FREEMARK's credentials?
MICHAEL FREEMARK's NPI is 1659434421. 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