2026 NPPES data Infectious Disease Physician NPI 1346286465 M.D.
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GREGG TOLLIVER, M.D.

Infectious Disease Physician in GREENBRAE, California. 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
84
Medicare Part D claims · 34 beneficiaries · Infectious Disease Physician avg: 816

What the federal data shows

GREGG TOLLIVER, M.D. filed 84 Medicare Part D claims in 2023 as a Infectious Disease Physician in GREENBRAE, California.

84
Part D claims, 2023
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.

GREGG TOLLIVER, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

84 0th percentile higher than 0% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 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)

GREGG TOLLIVER, 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 GREGG TOLLIVER, M.D.?

Quality data not reported

NPI registry status

Active

Issued 06/20/2006

NPI 1346286465

Primary specialty

Infectious Disease Physician

Mid-sized

8,292 US NPIs in this specialty

Medicare Part D claims

84 90% vs specialty avg

2023 prescription claims

Specialty avg: 816

Specialty distribution in California

How Infectious Disease Physician compares to other specialties among California providers

California providers

Infectious Disease Physician share within California

1. Infectious Disease Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Infectious Disease Physician share within California

Specialty board-certification context

Estimated specialty board-certified rate — Infectious Disease Physician (ABMS / AOA reference)

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

Est. board-certified rate (Infectious Disease Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Infectious Disease 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).

GREGG TOLLIVER, M.D. appears in the CMS NPPES registry as a Infectious Disease Physician provider holding M.D. credentials at 100A DRAKE'S LANDING ROAD, GREENBRAE, CA, 94904, with a listed phone of (415) 924-1214. NPI 1346286465 was issued on 06/20/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what TOLLIVER 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 84 prescription claims written by this provider, covering 34 Medicare beneficiaries and totaling roughly $14K in drug spend. 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.

Infectious Disease Physician is a mid-sized specialty nationwide, with 8,292 enrolled providers across 54 states and an average of 816 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

100A DRAKE'S LANDING ROAD
GREENBRAE, CA 94904

Provider Details

NPI 1346286465
Specialty Infectious Disease Physician
Credentials M.D.
Gender Male
NPI Issued 06/20/2006

Hospital and facility affiliations

Facilities where GREGG TOLLIVER, 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.

REGENTS UNIV OF CALIFORNIA UCSF
SAN FRANCISCO, CA

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 — California MBC 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 ~150K California medical licensees in 2023 — they are NOT specific to GREGG TOLLIVER, M.D.. To verify GREGG TOLLIVER, M.D.'s current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC 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 California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Medicare Part D Prescribing Data

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

84
Total Claims
$14K
Total Drug Cost
34
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
104
Total Day Supply
2,322
Generic Drug Cost
$7K
Antibiotic Claims
66

Patient Demographics

Average Patient Age
77.7 years
Avg HCC Risk Score
2.29
Gender Split
41% female / 59% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Cephalexin
19

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

Infectious Disease Physician Overview

How GREGG TOLLIVER, M.D. fits within the Infectious Disease Physician landscape nationally.

8,292
Infectious Disease Physician Providers in US
54
States with Infectious Disease Physician
816
Avg Claims per Provider

GREGG TOLLIVER, M.D.'s 84 claims are below the specialty average of 816.

Nearby Infectious Disease Physician Providers in California

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

Compare Infectious Disease Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is GREGG TOLLIVER, M.D.'s specialty?
GREGG TOLLIVER, M.D. specializes in Infectious Disease Physician and practices in GREENBRAE, California. Credentials: M.D..
How much does GREGG TOLLIVER, M.D. prescribe under Medicare Part D?
In 2023, GREGG TOLLIVER, M.D. wrote 84 Medicare Part D claims totaling $14K in drug costs for 34 beneficiaries.
Where is GREGG TOLLIVER, M.D. located?
GREGG TOLLIVER, M.D. is located at 100A DRAKE'S LANDING ROAD, GREENBRAE, CA, 94904. Phone: (415) 924-1214.
What is GREGG TOLLIVER, M.D.'s NPI number?
GREGG TOLLIVER, M.D.'s National Provider Identifier (NPI) is 1346286465, issued on 06/20/2006.
How many Infectious Disease Physician providers are there in the US?
There are 8,292 Infectious Disease Physician providers across 54 states in the US. The average Infectious Disease Physician provider writes 816 Medicare Part D claims per year.
What drugs does GREGG TOLLIVER, M.D. prescribe most often?
Based on 2023 Medicare Part D data, GREGG TOLLIVER, M.D.'s most frequently prescribed drugs include Cephalexin. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GREGG TOLLIVER, M.D. accept Medicare?
GREGG TOLLIVER, M.D. appears in CMS Medicare data with 84 Part D claims and 34 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GREGG TOLLIVER, M.D.'s credentials?
GREGG TOLLIVER, M.D.'s NPI is 1346286465 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