NPI registry status
Active
2026 NPPES data Rheumatology Physician NPI 1083770580 M.D.
Verify on CMS → Mark Tan, M.D.
Rheumatology Physician in Smithtown, New York.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 6,200 in Rheumatology 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
1K
Medicare Part D claims · 275 beneficiaries · Rheumatology Physician avg: 2K
Generic prescribing
63%
generic claims · 37% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
0/100
▼ 83 pts below national avg 83.1 · Penalty band
Industry payments
$3.0K
142 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Mark Tan, M.D. reported a CMS MIPS final score of 0/100 - below the 83.1 national average - and filed 1,438 Medicare Part D claims in 2023.
- 0/100
- MIPS score · -83 vs avg
- 1K
- Part D claims, 2023
- 63%
- 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.
Mark Tan, M.D.'s MIPS score vs every scored U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure
0 0th percentile higher than 0% of 477,587 scored providers
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
Where Mark Tan, M.D. sits
This provider among rheumatology physician peers
Across the 2,181 rheumatology physician providers who report both Medicare Part D prescribing and a MIPS quality score, Mark Tan, M.D. writes more Part D claims than 38% of them and scores higher on MIPS quality than 0% - placing this provider in the lower-volume, lower-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.
Part D claim volume vs MIPS quality, by specialty percentile
Each dot is one rheumatology physician peer from a representative sample of 60; the gold marker is Mark Tan, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
✓
Board certification likely (heuristic, not verified)
Mark Tan, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting - 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 Mark Tan, M.D.?
Below national averagePrimary specialty
Rheumatology Physician
Medicare Part D claims
1,438 30% vs specialty avg
MIPS final score
0/100 83.1 pts vs avg
Specialty distribution in New York
How Rheumatology Physician compares to other specialties among New York providers
Medicare quality performance, MIPS
Mark Tan, M.D.'s 2023 MIPS final score plotted against the Rheumatology Physician national average
- MIPS Final Score
- 0/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Rheumatology Physician) - 0/100 vs national avg 83.1
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).
Mark Tan, M.D. appears in the CMS NPPES registry as a Rheumatology Physician provider holding M.D. credentials at 222 MIDDLE COUNTRY ROAD, Smithtown, NY, 11787, with a listed phone of (631) 724-8900. NPI 1083770580 was issued on 12/29/2006.
Medicare Part D records for calendar year 2023 show 1,438 prescription claims written by this provider, covering 275 Medicare beneficiaries and totaling roughly $2.8 million in drug spend, split 37% brand-name and 63% generic by claim count, with an opioid prescribing rate of 3.5%. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 0/100 for the 2023 performance year (Quality 0), compared with the national average of 83.1.
Rheumatology Physician is a mid-sized specialty nationwide, with 6,200 enrolled providers across 52 states and an average of 2,054 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
Provider Details
| NPI | 1083770580 |
|---|---|
| Specialty | Rheumatology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 12/29/2006 |
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
0
Final Score
Avg: 83.1
0
Quality
Reporting: Individual
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 Mark Tan, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$3.0K
Largest payer
Janssen Biotech, 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.
License & disciplinary context - New York NYSBPMC 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 ~100K New York medical licensees in 2023 - they are NOT specific to Mark Tan, M.D.. To verify Mark Tan, M.D.'s current license status, search the NYSBPMC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
312
Total board actions, New York 2023
Across 302 cases
3.12
Actions per 1,000 licensees
New York statewide rate
probation
Most common action type
89 cases
NYSBPMC 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 New York disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Above average
Mark Tan, M.D. - brand share 37.0%
Rheumatology Physician average
37% brand-name claims vs 63% generic, on 1,438 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.
1,438
Total Claims
$2.8M
Total Drug Cost
275
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 2,261
- Total Day Supply
- 65,585
- Brand vs Generic
- 37% brand / 63% generic
- Brand Drug Cost
- $2.7M
- Generic Drug Cost
- $27K
- Opioid Claims
- 50 (3.5% rate)
- Antibiotic Claims
- 16
Patient Demographics
- Average Patient Age
- 72.8 years
- Avg HCC Risk Score
- 1.36
- Gender Split
- 71% female / 29% male
- Age Distribution
- <65: 32, 65-74: 111, 75-84: 108, 85+: 24
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Mark Tan, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Prednisone
Prednisone
208 claims
- Gabapentin
Gabapentin
118 claims
- Actemra
Actemra
107 claims
- Prolia
Prolia
84 claims
- Hydroxychloroquine… 80
Hydroxychloroquine Sulfate
80 claims
- Xeljanz Xr 41
Xeljanz Xr
41 claims
- Celecoxib 38
Celecoxib
38 claims
- Rinvoq 38
Rinvoq
38 claims
| Drug | Claims |
|---|---|
| Prednisone | 208 |
| Gabapentin | 118 |
| Actemra Tocilizumab | 107 |
| Prolia Denosumab | 84 |
| Hydroxychloroquine Sulfate | 80 |
| Xeljanz Xr Tofacitinib Citrate | 41 |
| Celecoxib | 38 |
| Rinvoq Upadacitinib | 38 |
| Allopurinol | 35 |
| Remicade Infliximab | 35 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Rheumatology Physician Overview
How Mark Tan, M.D. fits within the Rheumatology Physician landscape nationally.
6,200
Rheumatology Physician Providers in US
52
States with Rheumatology Physician
2,054
Avg Claims per Provider
Mark Tan, M.D.'s 1,438 claims are below the specialty average of 2,054.
Nearby Rheumatology Physician Providers in New York
Other clinicians with the same primary specialty enrolled in New York, drawn from the same CMS NPPES roster as Tan.
Dr. Mary Abdulky
MD
Syracuse, NY
Dr. Ilana Abeles
M.D., PHD
Rochester, NY
Dr. Jihad Abialmouna
M.D.
West Amherst, NY
Dr. Omar Abialmouna
MD
Buffalo, NY
Dr. Irina Abramova
D.O
New Hyde Park, NY
Compare Rheumatology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the New York medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Rheumatology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Mark Tan, M.D.'s specialty? ▼
Mark Tan, M.D. specializes in Rheumatology Physician and practices in Smithtown, New York. Credentials: M.D..
How much does Mark Tan, M.D. prescribe under Medicare Part D? ▼
In 2023, Mark Tan, M.D. wrote 1,438 Medicare Part D claims totaling $2.8M in drug costs for 275 beneficiaries.
What is Mark Tan, M.D.'s Medicare quality score? ▼
Mark Tan, M.D. has a CMS MIPS Final Score of 0/100 (Quality: 0). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Mark Tan, M.D. located? ▼
Mark Tan, M.D. is located at 222 MIDDLE COUNTRY ROAD, Smithtown, NY, 11787. Phone: (631) 724-8900.
What is Mark Tan, M.D.'s NPI number? ▼
Mark Tan, M.D.'s National Provider Identifier (NPI) is 1083770580, issued on 12/29/2006.
Does Mark Tan, M.D. prescribe more brand-name or generic drugs? ▼
Mark Tan, M.D.'s prescribing is 37% brand-name and 63% generic drugs by claim count, with $2.7M in brand drug costs.
Does Mark Tan, M.D. prescribe opioids? ▼
Yes, Mark Tan, M.D. had 50 opioid claims in 2023 with an opioid prescribing rate of 3.5%.
How many Rheumatology Physician providers are there in the US? ▼
There are 6,200 Rheumatology Physician providers across 52 states in the US. The average Rheumatology Physician provider writes 2,054 Medicare Part D claims per year.
What drugs does Mark Tan, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Mark Tan, M.D.'s most frequently prescribed drugs include Prednisone, Gabapentin, Actemra. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Mark Tan, M.D. accept Medicare? ▼
Mark Tan, M.D. appears in CMS Medicare data with 1,438 Part D claims and 275 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Mark Tan, M.D.'s credentials? ▼
Mark Tan, M.D.'s NPI is 1083770580 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.
- 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
Compiled from official public sources by the PlainDoctor editorial team.
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.