NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1518981307 M.D.
Verify on CMS → Michelle Tam, M.D.
Internal Medicine Physician in San Jose, 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 172,737 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
5K
Medicare Part D claims · 426 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
91%
generic claims · 8% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Michelle Tam, M.D. filed 4,531 Medicare Part D claims in 2023 as an Internal Medicine Physician in San Jose, California, prescribing 91% generic.
- 5K
- Part D claims, 2023
- 91%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥93rd
- 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.
CMS NPPES provider registry desk
NPI 1518981307 · Internal Medicine Physician
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-MID · BOOK-MID · PHOTO-ENUM
- NPI-10 1518981307
- ENUM-LEGACY 2006
- TAX-MEGA 173K Internal Medicine
- RX-MID 4,531
- BOOK-MID 20,046 in California
- PHOTO-ENUM Richard Weinberg · 2006
Michelle Tam, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
4,531 ≥ 93rd percentile 93% of 1,370,886 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 · 2023
✓
Board certification likely (heuristic, not verified)
Michelle Tam, 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 Michelle Tam, M.D.?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
4,531 67% 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 | 1518981307 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 07/26/2006 |
Hospital and facility affiliations
Facilities where Michelle Tam, 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.
North East Medical Services
San Jose, 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 Michelle Tam, M.D.. To verify Michelle Tam, 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 · Generic-heavy
Michelle Tam, M.D. - brand share 8.0%
Internal Medicine Physician average
8% brand-name claims vs 91% generic, on 4,531 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.
4,531
Total Claims
$250K
Total Drug Cost
426
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 11,327
- Total Day Supply
- 332,703
- Brand vs Generic
- 8% brand / 91% generic
- Brand Drug Cost
- $163K
- Generic Drug Cost
- $86K
- Opioid Claims
- 25 (0.6% rate)
- Antibiotic Claims
- 35
Patient Demographics
- Average Patient Age
- 75.4 years
- Avg HCC Risk Score
- 0.88
- Gender Split
- 62% female / 38% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Michelle Tam, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
687 claims
- Amlodipine Besylate
Amlodipine Besylate
567 claims
- Losartan Potassium
Losartan Potassium
419 claims
- Metformin Hcl 199
Metformin Hcl
199 claims
- Simvastatin 186
Simvastatin
186 claims
- Lisinopril 168
Lisinopril
168 claims
- Levothyroxine Sodium 113
Levothyroxine Sodium
113 claims
- Alendronate Sodium 108
Alendronate Sodium
108 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 687 |
| Amlodipine Besylate | 567 |
| Losartan Potassium | 419 |
| Metformin Hcl | 199 |
| Simvastatin | 186 |
| Lisinopril | 168 |
| Levothyroxine Sodium | 113 |
| Alendronate Sodium | 108 |
| Tamsulosin Hcl | 108 |
| Metoprolol Succinate | 101 |
* 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 Michelle Tam, M.D. fits within the Internal Medicine Physician landscape nationally.
172,737
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider
Michelle Tam, M.D.'s 4,531 claims are above the specialty average of 2,716.
Nationwide Internal Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Tam, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
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 Tam.
One of 20,046 Internal Medicine Physician providers enrolled in California, 5 are shown here.
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
Compare Internal Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Michelle Tam, M.D.'s specialty? ▼
Michelle Tam, M.D. specializes in Internal Medicine Physician and practices in San Jose, California. Credentials: M.D..
How much does Michelle Tam, M.D. prescribe under Medicare Part D? ▼
In 2023, Michelle Tam, M.D. wrote 4,531 Medicare Part D claims totaling $250K in drug costs for 426 beneficiaries.
Where is Michelle Tam, M.D. located? ▼
Michelle Tam, M.D. is located at 1870 LUNDY AVE, San Jose, CA, 95131. Phone: (408) 573-9686.
What is Michelle Tam, M.D.'s NPI number? ▼
Michelle Tam, M.D.'s National Provider Identifier (NPI) is 1518981307, issued on 07/26/2006.
Does Michelle Tam, M.D. prescribe more brand-name or generic drugs? ▼
Michelle Tam, M.D.'s prescribing is 8% brand-name and 91% generic drugs by claim count, with $163K in brand drug costs.
Does Michelle Tam, M.D. prescribe opioids? ▼
Yes, Michelle Tam, M.D. had 25 opioid claims in 2023 with an opioid prescribing rate of 0.6%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 172,737 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 Michelle Tam, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Michelle Tam, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Michelle Tam, M.D. accept Medicare? ▼
Michelle Tam, M.D. appears in CMS Medicare data with 4,531 Part D claims and 426 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Michelle Tam, M.D.'s credentials? ▼
Michelle Tam, M.D.'s NPI is 1518981307 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 (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
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 May 2026.