NPI registry status
Active
2026 NPPES data Hematology (Internal Medicine) Physician NPI 1902894991 D.O.
Verify on CMS → William Derosa, D.O.
Hematology (Internal Medicine) Physician in Morristown, New Jersey.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 1,483 in Hematology (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
735
Medicare Part D claims · 114 beneficiaries · Hematology (Internal Medicine) Physician avg: 684
Generic prescribing
61%
generic claims · 39% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
William Derosa, D.O. filed 735 Medicare Part D claims in 2024 as a Hematology (Internal Medicine) Physician in Morristown, New Jersey, prescribing 61% generic.
- 735
- Part D claims, 2024
- 61%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥70th
- 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 William Derosa, D.O.
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 1902894991), first enumerated 10/12/2005.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 735 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
- 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.
CMS NPPES provider registry desk
NPI 1902894991 · Hematology (Internal Medicine) Physician
NPI-10 · ENUM-LEGACY · TAX-NARROW · RX-LIGHT · BOOK-THIN · PHOTO-ENUM
- NPI-10 1902894991
- ENUM-LEGACY 2005
- TAX-NARROW 1,483
- RX-LIGHT 735
- BOOK-THIN 48 in New Jersey
- PHOTO-ENUM Visaharan Sivasubram… · 2005
William Derosa, D.O.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
735 ≥ 70th percentile 70% 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)
William Derosa, D.O. 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 William Derosa, D.O.?
Quality data not reportedPrimary specialty
Hematology (Internal Medicine) Physician
Medicare Part D claims
735 7% vs specialty avg
Specialty distribution in New Jersey
How Hematology (Internal Medicine) Physician compares to other specialties among New Jersey 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 (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 | 1902894991 |
|---|---|
| Specialty | Hematology (Internal Medicine) Physician |
| Credentials | D.O. |
| Gender | Male |
| NPI Issued | 10/12/2005 |
Hospital and facility affiliations
Facilities where William Derosa, D.O. 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.
Barnabas Health Medical Group PC
Belleville, NJ
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Brand vs generic prescribing mix · Above average
William Derosa, D.O. - brand share 39.0%
Hematology (Internal Medicine) Physician average
39% brand-name claims vs 61% generic, on 735 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.
735
Total Claims
$3.1M
Total Drug Cost
114
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,133.7
- Total Day Supply
- 32,088
- Brand vs Generic
- 39% brand / 61% generic
- Brand Drug Cost
- $2.7M
- Generic Drug Cost
- $349K
- Antibiotic Claims
- 54
Patient Demographics
- Average Patient Age
- 76.4 years
- Avg HCC Risk Score
- 2.49
- Gender Split
- 46% female / 54% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What William Derosa, D.O. prescribes most
Top Medicare Part D drugs by claim count, 2024
- Eliquis
Eliquis
67 claims
- Jakafi
Jakafi
47 claims
- Sulfamethoxazole-T…
Sulfamethoxazole-Trimethoprim
37 claims
- Famciclovir
Famciclovir
28 claims
- Acyclovir
Acyclovir
27 claims
- Hydroxyurea
Hydroxyurea
27 claims
- Allopurinol 24
Allopurinol
24 claims
- Anastrozole 24
Anastrozole
24 claims
| Drug | Claims |
|---|---|
| Eliquis Apixaban | 67 |
| Jakafi Ruxolitinib Phosphate | 47 |
| Sulfamethoxazole-Trimethoprim Sulfamethoxazole/Trimethoprim | 37 |
| Famciclovir | 28 |
| Acyclovir | 27 |
| Hydroxyurea | 27 |
| Allopurinol | 24 |
| Anastrozole | 24 |
| Venclexta Venetoclax | 24 |
| Xarelto Rivaroxaban | 24 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Hematology (Internal Medicine) Physician in NJ →
All providers in New Jersey →
Compare specialties →
Hematology (Internal Medicine) Physician Overview
How William Derosa, D.O. fits within the Hematology (Internal Medicine) Physician landscape nationally.
1,483
Hematology (Internal Medicine) Physician Providers in US
50
States with Hematology (Internal Medicine) Physician
684
Avg Claims per Provider
William Derosa, D.O.'s 735 claims are above the specialty average of 684.
Nationwide Hematology (Internal Medicine) Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Derosa, both outside New Jersey 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 Hematology (Internal Medicine) Physician Providers in New Jersey
Other clinicians with the same primary specialty enrolled in New Jersey, drawn from the same CMS NPPES roster as Derosa.
One of 48 Hematology (Internal Medicine) Physician providers enrolled in New Jersey, 5 are shown here.
Dr. Robert Alter
MD
Hackensack, NJ
Dr. Fazal Bari
M.D.
Mountain Lakes, NJ
Dr. Noa Biran
M.D.
Hackensack, NJ
Marcus Carr
North Brunswick, NJ
Dr. Allan Louie Cruz
M.D.
Jersey City, NJ
Compare Hematology (Internal Medicine) Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is William Derosa, D.O.'s specialty? ▼
William Derosa, D.O. specializes in Hematology (Internal Medicine) Physician and practices in Morristown, New Jersey. Credentials: D.O..
How much does William Derosa, D.O. prescribe under Medicare Part D? ▼
In 2024, William Derosa, D.O. wrote 735 Medicare Part D claims totaling $3.1M in drug costs for 114 beneficiaries.
Where is William Derosa, D.O. located? ▼
William Derosa, D.O. is located at 95 MADISON AVE, Morristown, NJ, 07960. Phone: (973) 538-5210.
What is William Derosa, D.O.'s NPI number? ▼
William Derosa, D.O.'s National Provider Identifier (NPI) is 1902894991, issued on 10/12/2005.
Does William Derosa, D.O. prescribe more brand-name or generic drugs? ▼
William Derosa, D.O.'s prescribing is 39% brand-name and 61% generic drugs by claim count, with $2.7M in brand drug costs.
How many Hematology (Internal Medicine) Physician providers are there in the US? ▼
There are 1,483 Hematology (Internal Medicine) Physician providers across 50 states in the US. The average Hematology (Internal Medicine) Physician provider writes 684 Medicare Part D claims per year.
What drugs does William Derosa, D.O. prescribe most often? ▼
Based on 2024 Medicare Part D data, William Derosa, D.O.'s most frequently prescribed drugs include Eliquis, Jakafi, Sulfamethoxazole-Trimethoprim. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Derosa, D.O. accept Medicare? ▼
William Derosa, D.O. appears in CMS Medicare data with 735 Part D claims and 114 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Derosa, D.O.'s credentials? ▼
William Derosa, D.O.'s NPI is 1902894991 with credentials D.O.. 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.