NPI registry status
Active
2026 NPPES data Hematology & Oncology Physician NPI 1679684476 MD
Verify on CMS → Frederick Fellin, MD
Hematology & Oncology Physician in Philadelphia, Pennsylvania.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 11,215 in Hematology & Oncology 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
801
Medicare Part D claims · 173 beneficiaries · Hematology & Oncology Physician avg: 847
Generic prescribing
68%
generic claims · 32% brand-name · higher generic rates reduce patient out-of-pocket costs
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
Frederick Fellin, MD filed 801 Medicare Part D claims in 2023 as a Hematology & Oncology Physician in Philadelphia, Pennsylvania, prescribing 68% generic.
- 801
- Part D claims, 2023
- 68%
- 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.
Frederick Fellin, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
801 Top 27% higher than 73% of 1,370,886 prescribers
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)
Frederick Fellin, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 3 hospital affiliations - 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 Frederick Fellin, MD?
Quality data not reportedPrimary specialty
Hematology & Oncology Physician
Medicare Part D claims
801 5% vs specialty avg
Specialty distribution in Pennsylvania
How Hematology & Oncology Physician compares to other specialties among Pennsylvania 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 Hematology & Oncology 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).
Frederick Fellin, MD appears in the CMS NPPES registry as a Hematology & Oncology Physician provider holding MD credentials at 925 CHESTNUT STREET, Philadelphia, PA, 19107, with a listed phone of (215) 955-8874. NPI 1679684476 was issued on 08/31/2006.
Medicare Part D records for calendar year 2023 show 801 prescription claims written by this provider, covering 173 Medicare beneficiaries and totaling roughly $3.2 million in drug spend, split 32% brand-name and 68% generic by claim count, with an opioid prescribing rate of 5.5%.
Hematology & Oncology Physician is a mid-sized specialty nationwide, with 11,215 enrolled providers across 54 states and an average of 847 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 | 1679684476 |
|---|---|
| Specialty | Hematology & Oncology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 08/31/2006 |
Hospital and facility affiliations
Facilities where Frederick Fellin, 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.
According to CMS billing records, Frederick Fellin, MD is affiliated with 3 Medicare-billing facilities.
Abington Memorial Hospital
Willow Grove, PA
Jefferson University Physicians
Philadelphia, PA
Novacare Outpatient Rehabilitation East, Inc.
Collegeville, PA
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 - Pennsylvania PA-BOM 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 ~45K Pennsylvania medical licensees in 2023 - they are NOT specific to Frederick Fellin, MD. To verify Frederick Fellin, MD's current license status, search the PA-BOM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
133
Total board actions, Pennsylvania 2023
Across 129 cases
2.96
Actions per 1,000 licensees
Pennsylvania statewide rate
probation
Most common action type
48 cases
PA-BOM 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 Pennsylvania disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Above average
Frederick Fellin, MD - brand share 32.0%
Hematology & Oncology Physician average
32% brand-name claims vs 68% generic, on 801 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.
801
Total Claims
$3.2M
Total Drug Cost
173
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,462
- Total Day Supply
- 41,206
- Brand vs Generic
- 32% brand / 68% generic
- Brand Drug Cost
- $3.2M
- Generic Drug Cost
- $60K
- Opioid Claims
- 44 (5.5% rate)
Patient Demographics
- Average Patient Age
- 73.6 years
- Avg HCC Risk Score
- 1.98
- Gender Split
- 84% female / 16% male
- Age Distribution
- <65: 19, 65-74: 75, 75-84: 63, 85+: 16
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Frederick Fellin, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Anastrozole
Anastrozole
143 claims
- Ibrance
Ibrance
87 claims
- Letrozole 39
Letrozole
39 claims
- Tamoxifen Citrate 38
Tamoxifen Citrate
38 claims
- Ondansetron Hcl 36
Ondansetron Hcl
36 claims
- Tagrisso 36
Tagrisso
36 claims
- Exemestane 28
Exemestane
28 claims
- Hydroxyurea 27
Hydroxyurea
27 claims
| Drug | Claims |
|---|---|
| Anastrozole | 143 |
| Ibrance Palbociclib | 87 |
| Letrozole | 39 |
| Tamoxifen Citrate | 38 |
| Ondansetron Hcl | 36 |
| Tagrisso Osimertinib Mesylate | 36 |
| Exemestane | 28 |
| Hydroxyurea | 27 |
| Imbruvica Ibrutinib | 24 |
| Eliquis Apixaban | 23 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Hematology & Oncology Physician Overview
How Frederick Fellin, MD fits within the Hematology & Oncology Physician landscape nationally.
11,215
Hematology & Oncology Physician Providers in US
54
States with Hematology & Oncology Physician
847
Avg Claims per Provider
Frederick Fellin, MD's 801 claims are below the specialty average of 847.
Nearby Hematology & Oncology Physician Providers in Pennsylvania
Other clinicians with the same primary specialty enrolled in Pennsylvania, drawn from the same CMS NPPES roster as Fellin.
Dr. Abdullateef Abdulkareem
M.D.
Lancaster, PA
Dr. Charles Abrams
MD
Philadelphia, PA
Tala Achkar
Pittsburgh, PA
Dr. Monica Adedeji
MD, MPH
Hershey, PA
Dr. Giridhar Adiga
MD
Ephrata, PA
Compare Hematology & Oncology 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 Pennsylvania medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Hematology & Oncology 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 Frederick Fellin, MD's specialty? ▼
Frederick Fellin, MD specializes in Hematology & Oncology Physician and practices in Philadelphia, Pennsylvania. Credentials: MD.
How much does Frederick Fellin, MD prescribe under Medicare Part D? ▼
In 2023, Frederick Fellin, MD wrote 801 Medicare Part D claims totaling $3.2M in drug costs for 173 beneficiaries.
Where is Frederick Fellin, MD located? ▼
Frederick Fellin, MD is located at 925 CHESTNUT STREET, Philadelphia, PA, 19107. Phone: (215) 955-8874.
What is Frederick Fellin, MD's NPI number? ▼
Frederick Fellin, MD's National Provider Identifier (NPI) is 1679684476, issued on 08/31/2006.
Does Frederick Fellin, MD prescribe more brand-name or generic drugs? ▼
Frederick Fellin, MD's prescribing is 32% brand-name and 68% generic drugs by claim count, with $3.2M in brand drug costs.
Does Frederick Fellin, MD prescribe opioids? ▼
Yes, Frederick Fellin, MD had 44 opioid claims in 2023 with an opioid prescribing rate of 5.5%.
How many Hematology & Oncology Physician providers are there in the US? ▼
There are 11,215 Hematology & Oncology Physician providers across 54 states in the US. The average Hematology & Oncology Physician provider writes 847 Medicare Part D claims per year.
What drugs does Frederick Fellin, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Frederick Fellin, MD's most frequently prescribed drugs include Anastrozole, Ibrance, Letrozole. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Frederick Fellin, MD accept Medicare? ▼
Frederick Fellin, MD appears in CMS Medicare data with 801 Part D claims and 173 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Frederick Fellin, MD's credentials? ▼
Frederick Fellin, MD's NPI is 1679684476 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
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
Compiled from official public sources by the PlainDoctor editorial team.