NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1588650667 M.D.
Verify on CMS → John Gilbert, M.D.
Internal Medicine Physician in Fullerton, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 174,792 in Internal Medicine Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
12K
Medicare Part D claims · 1K beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
64%
generic claims · 32% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$38.7K
113 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
John Gilbert, M.D. filed 11,752 Medicare Part D claims in 2024 as an Internal Medicine Physician in Fullerton, California, prescribing 64% generic.
- 12K
- Part D claims, 2024
- 64%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥98th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about John Gilbert, M.D.
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1588650667), first enumerated 09/23/2005.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 11,752 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Heuristic suggests board-certified status based on ABMS-eligible specialty taxonomy plus active CMS participation signals — not a direct ABMS verification.
- Reported
Hospital affiliations
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- Reported
Industry payment transparency
$38.7K in reported industry payments (113 transfers) in 2024 under the federal Sunshine Act — disclosed transfers of value, not a quality rating.
Source: CMS Open Payments
- State context
State board disciplinary context
California statewide board action statistics are published annually — these figures describe aggregate state activity, not John Gilbert, M.D.'s individual license status. Verify directly with the state medical board.
Source: MBC annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
Compare Gilbert with other Internal Medicine Physician providers
Same primary specialty, same federal CMS NPPES roster.
All 63 Internal Medicine Physician providers in Fullerton, CA →
Also enrolled in California
- Dr. Jacob Aaron, MD San Francisco, CA
- Dr. Alistair Aaronson, MD Stanford, CA
- Dr. Jose Abad., MD Sacramento, CA
- Dr. Donna Abare, MD Oakland, CA
- Marce Abare Scotts Valley, CA
- Dr. Samuel Abarte, M.D. Chula Vista, CA
Other specialties in Fullerton: Behavior Technician (2,141) · Student in an Organized Health Care Education/Training Program (282) · Marriage & Family Therapist (251) · Pharmacist (145)
CMS NPPES provider registry desk
NPI 1588650667 · Internal Medicine Physician
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-HEAVY · BOOK-MID · PHOTO-ENUM
- NPI-10 1588650667
- ENUM-LEGACY 2005
- TAX-MEGA 175K Internal Medicine
- RX-HEAVY 12K claims
- BOOK-MID 20,403 in California
- PHOTO-ENUM Gregory Doak, MD · 2005
John Gilbert, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
11,752 ≥ 98th percentile 98% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
✓
Board certification likely (heuristic, not verified)
John Gilbert, 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 John Gilbert, M.D.?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
11,752 322% vs specialty avg
Specialty distribution in California
How Internal Medicine Physician compares to other specialties among California providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Internal Medicine Physician. Verify directly:
How MIPS and board certification work
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).
Practice Address
Provider Details
| NPI | 1588650667 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 09/23/2005 |
Hospital and facility affiliations
Facilities where John Gilbert, 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.
Providence Medical Foundation
Fullerton, 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).
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 John Gilbert, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$38.7K
Largest payer
Abbott Laboratories
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.
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 John Gilbert, M.D.. To verify John Gilbert, 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.
Brand vs generic prescribing mix · Above average
John Gilbert, M.D. - brand share 32.0%
Internal Medicine Physician average
32% brand-name claims vs 64% generic, on 11,752 2024 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 2024.
11,752
Total Claims
$3.7M
Total Drug Cost
1,100
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 29,747.3
- Total Day Supply
- 887,008
- Brand vs Generic
- 32% brand / 64% generic
- Brand Drug Cost
- $3.5M
- Generic Drug Cost
- $159K
- Opioid Claims
- 13 (0.1% rate)
- Antibiotic Claims
- 27
Patient Demographics
- Average Patient Age
- 75.6 years
- Avg HCC Risk Score
- 1.63
- Gender Split
- 62% female / 38% male
- Age Distribution
- <65: 40, 65-74: 458, 75-84: 462, 85+: 140
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What John Gilbert, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2024
- Levothyroxine Sodium
Levothyroxine Sodium
1,122 claims
- Metformin Hcl Er
Metformin Hcl Er
581 claims
- Ozempic
Ozempic
562 claims
- Atorvastatin Calcium
Atorvastatin Calcium
543 claims
- Farxiga
Farxiga
490 claims
- Synthroid 391
Synthroid
391 claims
- Metformin Hcl 390
Metformin Hcl
390 claims
- Pioglitazone Hcl 388
Pioglitazone Hcl
388 claims
| Drug | Claims |
|---|---|
| Levothyroxine Sodium | 1,122 |
| Metformin Hcl Er Metformin Hcl | 581 |
| Ozempic Semaglutide | 562 |
| Atorvastatin Calcium | 543 |
| Farxiga Dapagliflozin Propanediol | 490 |
| Synthroid Levothyroxine Sodium | 391 |
| Metformin Hcl | 390 |
| Pioglitazone Hcl | 388 |
| Rosuvastatin Calcium | 339 |
| Jardiance Empagliflozin | 333 |
* 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 John Gilbert, M.D. fits within the Internal Medicine Physician landscape nationally.
174,792
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,785
Avg Claims per Provider
John Gilbert, M.D.'s 11,752 claims are above the specialty average of 2,785.
Nationwide Internal Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Gilbert, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2005)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Internal Medicine Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Gilbert.
One of 20,403 Internal Medicine Physician providers enrolled in California, 11 are shown on this page.
Dr. Alexander Abary
MD
Long Beach, CA
Dr. Luba Abascal
MD
San Francisco, CA
Dr. Michael Abate
MD
Sacramento, CA
Dr. Wali Abawi
D.O.
Joshua Tree, CA
Hazel Abaya
Thousand Oaks, CA
Compare Internal Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is John Gilbert, M.D.'s specialty? ▼
John Gilbert, M.D. specializes in Internal Medicine Physician and practices in Fullerton, California. Credentials: M.D..
How much does John Gilbert, M.D. prescribe under Medicare Part D? ▼
In 2024, John Gilbert, M.D. wrote 11,752 Medicare Part D claims totaling $3.7M in drug costs for 1,100 beneficiaries.
Where is John Gilbert, M.D. located? ▼
John Gilbert, M.D. is located at 100 E VALENCIA MESA DR, Fullerton, CA, 92835. Phone: (714) 446-5640.
What is John Gilbert, M.D.'s NPI number? ▼
John Gilbert, M.D.'s National Provider Identifier (NPI) is 1588650667, issued on 09/23/2005.
Does John Gilbert, M.D. prescribe more brand-name or generic drugs? ▼
John Gilbert, M.D.'s prescribing is 32% brand-name and 64% generic drugs by claim count, with $3.5M in brand drug costs.
Does John Gilbert, M.D. prescribe opioids? ▼
Yes, John Gilbert, M.D. had 13 opioid claims in 2024 with an opioid prescribing rate of 0.1%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 174,792 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,785 Medicare Part D claims per year.
What drugs does John Gilbert, M.D. prescribe most often? ▼
Based on 2024 Medicare Part D data, John Gilbert, M.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Metformin Hcl Er, Ozempic. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does John Gilbert, M.D. accept Medicare? ▼
John Gilbert, M.D. appears in CMS Medicare data with 11,752 Part D claims and 1,100 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify John Gilbert, M.D.'s credentials? ▼
John Gilbert, M.D.'s NPI is 1588650667 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
View source datasets and methodology notes
- 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 (2024). 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 August 2026 (NPPES) / 2024 (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
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.