NPI registry status
Active
2026 NPPES data Family Medicine Physician NPI 1598798621 M.D.
Verify on CMS → William Royster, M.D.
Family Medicine Physician in Hagerstown, Maryland.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 147,760 in Family 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
8K
Medicare Part D claims · 582 beneficiaries · Family Medicine Physician avg: 3K
Generic prescribing
87%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$33.55
1 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
William Royster, M.D. filed 8,245 Medicare Part D claims in 2023 as a Family Medicine Physician in Hagerstown, Maryland, prescribing 87% generic.
- 8K
- Part D claims, 2023
- 87%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥97th
- 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 1598798621 · Family Medicine Physician
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-MID · BOOK-LIGHT · PHOTO-ENUM
- NPI-10 1598798621
- ENUM-LEGACY 2006
- TAX-MEGA 148K Family Medicine
- RX-MID 8,245
- BOOK-LIGHT 1,865 in Maryland
- PHOTO-ENUM Mark Brooks · 2006
William Royster, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
8,245 ≥ 97th percentile 97% 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)
William Royster, M.D. 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 William Royster, M.D.?
Quality data not reportedPrimary specialty
Family Medicine Physician
Medicare Part D claims
8,245 141% vs specialty avg
Specialty distribution in Maryland
How Family Medicine Physician compares to other specialties among Maryland 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 Family 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 | 1598798621 |
|---|---|
| Specialty | Family Medicine Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 07/09/2006 |
Hospital and facility affiliations
Facilities where William Royster, 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.
According to CMS billing records, William Royster, M.D. is affiliated with 3 Medicare-billing facilities.
Medical Practices OF Antietam, LLC
Hagerstown, MD
Meritus Medical Center Inc
Hagerstown, MD
Meritus Urgent Care LLC
Hagerstown, MD
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 William Royster, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$34
Largest payer
MY01 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.
Brand vs generic prescribing mix · Typical
William Royster, M.D. - brand share 12.0%
Family Medicine Physician average
12% brand-name claims vs 87% generic, on 8,245 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.
8,245
Total Claims
$799K
Total Drug Cost
582
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 18,480
- Total Day Supply
- 544,518
- Brand vs Generic
- 12% brand / 87% generic
- Brand Drug Cost
- $653K
- Generic Drug Cost
- $141K
- Opioid Claims
- 27 (0.3% rate)
- Antibiotic Claims
- 102
Patient Demographics
- Average Patient Age
- 71.5 years
- Avg HCC Risk Score
- 1.17
- Gender Split
- 60% female / 40% male
- Age Distribution
- <65: 88, 65-74: 279, 75-84: 161, 85+: 54
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What William Royster, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
559 claims
- Amlodipine Besylate
Amlodipine Besylate
444 claims
- Lisinopril
Lisinopril
373 claims
- Levothyroxine Sodium
Levothyroxine Sodium
284 claims
- Omeprazole
Omeprazole
236 claims
- Metformin Hcl Er 215
Metformin Hcl Er
215 claims
- Metoprolol Succinate 181
Metoprolol Succinate
181 claims
- Losartan Potassium 173
Losartan Potassium
173 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 559 |
| Amlodipine Besylate | 444 |
| Lisinopril | 373 |
| Levothyroxine Sodium | 284 |
| Omeprazole | 236 |
| Metformin Hcl Er Metformin Hcl | 215 |
| Metoprolol Succinate | 181 |
| Losartan Potassium | 173 |
| Buspirone Hcl | 147 |
| Glimepiride | 137 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Family Medicine Physician Overview
How William Royster, M.D. fits within the Family Medicine Physician landscape nationally.
147,760
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider
William Royster, M.D.'s 8,245 claims are above the specialty average of 3,418.
Nationwide Family Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Royster, both outside Maryland 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 Family Medicine Physician Providers in Maryland
Other clinicians with the same primary specialty enrolled in Maryland, drawn from the same CMS NPPES roster as Royster.
One of 1,865 Family Medicine Physician providers enrolled in Maryland, 5 are shown here.
Dr. Amelia Abban
CRNP-BC
Laurel, MD
Dr. Peter Abbott
MD
Willards, MD
Dr. Hanan Aboumatar
MD, MPH
Baltimore, MD
Dr. Ndubuisi Achufusi
M.D.
Greenbelt, MD
Dr. Jose Acol
MD
Mount Airy, MD
Compare Family Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is William Royster, M.D.'s specialty? ▼
William Royster, M.D. specializes in Family Medicine Physician and practices in Hagerstown, Maryland. Credentials: M.D..
How much does William Royster, M.D. prescribe under Medicare Part D? ▼
In 2023, William Royster, M.D. wrote 8,245 Medicare Part D claims totaling $799K in drug costs for 582 beneficiaries.
Where is William Royster, M.D. located? ▼
William Royster, M.D. is located at 11110 MEDICAL CAMPUS RD STE 200, Hagerstown, MD, 21742. Phone: (301) 714-4400.
What is William Royster, M.D.'s NPI number? ▼
William Royster, M.D.'s National Provider Identifier (NPI) is 1598798621, issued on 07/09/2006.
Does William Royster, M.D. prescribe more brand-name or generic drugs? ▼
William Royster, M.D.'s prescribing is 12% brand-name and 87% generic drugs by claim count, with $653K in brand drug costs.
Does William Royster, M.D. prescribe opioids? ▼
Yes, William Royster, M.D. had 27 opioid claims in 2023 with an opioid prescribing rate of 0.3%.
How many Family Medicine Physician providers are there in the US? ▼
There are 147,760 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does William Royster, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, William Royster, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Lisinopril. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Royster, M.D. accept Medicare? ▼
William Royster, M.D. appears in CMS Medicare data with 8,245 Part D claims and 582 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Royster, M.D.'s credentials? ▼
William Royster, M.D.'s NPI is 1598798621 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.