2026 NPPES data Internal Medicine Physician NPI 1083948285 MD
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WALTER MAZZEI, MD

Internal Medicine Physician in COLUMBIA, South 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
3K
Medicare Part D claims · 458 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
75%
generic claims · 25% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
99.3294/100
▲ 16 pts above national avg 83.1 · [object Object]
Industry payments
$1.8K
94 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WALTER MAZZEI, MD reported a CMS MIPS final score of 99.3294/100 — above the 83.1 national average — and filed 3,054 Medicare Part D claims in 2023.

99.3294/100
MIPS score · +16 vs avg
3K
Part D claims, 2023
75%
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.

WALTER MAZZEI, MD's MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

99 Top 9% higher than 91% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). Below this entry. 80–90: 129,887 scored providers (27%). Below this entry. 90–100: 189,403 scored providers (40%). This entry sits in this band. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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 Merit-based Incentive Payment System (MIPS) · 2023

Board certification likely (heuristic — not verified)

WALTER MAZZEI, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 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 WALTER MAZZEI, MD?

High performer (top quartile)

NPI registry status

Active

Issued 09/22/2009

NPI 1083948285

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

3,054 12% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

MIPS final score

99.3294/100 16.229400000000012% pts

Exceptional band

vs 83.1 national avg

Specialty distribution in South Carolina

How Internal Medicine Physician compares to other specialties among South Carolina providers

South Carolina providers

Internal Medicine Physician share within South Carolina

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

Medicare quality performance — MIPS

WALTER MAZZEI, MD's 2023 MIPS final score plotted against the Internal Medicine Physician national average

High performer (top quartile)
MIPS Final Score
99.3294/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Internal Medicine Physician) — 99.3294/100 vs national avg 83.1

0%100%National avg83%99%
MIPS final score (Internal Medicine Physician) — 99.3294/100 vs national avg 83.1

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).

WALTER MAZZEI, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 8 RICHLAND MEDICAL PARK DR, COLUMBIA, SC, 29203, with a listed phone of (803) 256-6511. NPI 1083948285 was issued on 09/22/2009. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MAZZEI 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 3,054 prescription claims written by this provider, covering 458 Medicare beneficiaries and totaling roughly $869K in drug spend, split 25% brand-name and 75% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 99.3294/100 for the 2023 performance year (Quality 90.5979), compared with the national average of 83.1.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

8 RICHLAND MEDICAL PARK DR
COLUMBIA, SC 29203

Provider Details

NPI 1083948285
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 09/22/2009

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

99.3294
Final Score
Avg: 83.1
90.5979
Quality
100
Promoting Interoperability

Reporting: Alternative Payment Model

Hospital and facility affiliations

Facilities where WALTER MAZZEI, MD 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.

PRISMA HEALTH MEDICAL GROUP-MIDLANDS
COLUMBIA, SC

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

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for WALTER MAZZEI, MD. Source: openpaymentsdata.cms.gov.

Total received

$1.8K

Largest payer

Medtronic, Inc.

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

Brand vs generic prescribing mix · Above average

WALTER MAZZEI, MD — brand share 25.0%
Specialty average (est.)

25% brand-name claims vs 75% generic, on 3,054 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.

3,054
Total Claims
$869K
Total Drug Cost
458
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
7,241
Total Day Supply
214,552
Brand vs Generic
25% brand / 75% generic
Brand Drug Cost
$800K
Generic Drug Cost
$69K
Antibiotic Claims
12

Patient Demographics

Average Patient Age
74.4 years
Avg HCC Risk Score
1.44
Gender Split
46% female / 54% male
Age Distribution
<65: 24, 65-74: 210, 75-84: 179, 85+: 45

Top Prescribed Drugs (Medicare Part D)

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

What WALTER MAZZEI, MD 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
Eliquis
Apixaban
486
Metoprolol Succinate
298
Sotalol
Sotalol Hcl
242
Xarelto
Rivaroxaban
161
Flecainide Acetate
148
Atorvastatin Calcium
145
Metoprolol Tartrate
120
Furosemide
99
Amiodarone Hcl
98
Losartan Potassium
98

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

Internal Medicine Physician Overview

How WALTER MAZZEI, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

WALTER MAZZEI, MD's 3,054 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in South Carolina

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

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

Frequently Asked Questions

What is WALTER MAZZEI, MD's specialty?
WALTER MAZZEI, MD specializes in Internal Medicine Physician and practices in COLUMBIA, South Carolina. Credentials: MD.
How much does WALTER MAZZEI, MD prescribe under Medicare Part D?
In 2023, WALTER MAZZEI, MD wrote 3,054 Medicare Part D claims totaling $869K in drug costs for 458 beneficiaries.
What is WALTER MAZZEI, MD's Medicare quality score?
WALTER MAZZEI, MD has a CMS MIPS Final Score of 99.3294/100 (Quality: 90.5979). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is WALTER MAZZEI, MD located?
WALTER MAZZEI, MD is located at 8 RICHLAND MEDICAL PARK DR, COLUMBIA, SC, 29203. Phone: (803) 256-6511.
What is WALTER MAZZEI, MD's NPI number?
WALTER MAZZEI, MD's National Provider Identifier (NPI) is 1083948285, issued on 09/22/2009.
Does WALTER MAZZEI, MD prescribe more brand-name or generic drugs?
WALTER MAZZEI, MD's prescribing is 25% brand-name and 75% generic drugs by claim count, with $800K in brand drug costs.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does WALTER MAZZEI, MD prescribe most often?
Based on 2023 Medicare Part D data, WALTER MAZZEI, MD's most frequently prescribed drugs include Eliquis, Metoprolol Succinate, Sotalol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WALTER MAZZEI, MD accept Medicare?
WALTER MAZZEI, MD appears in CMS Medicare data with 3,054 Part D claims and 458 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WALTER MAZZEI, MD's credentials?
WALTER MAZZEI, MD's NPI is 1083948285 with credentials MD. 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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