NPI registry status
Active
2026 NPPES data Rheumatology Physician NPI 1518942184 M.D.
Verify on CMS → William Mullins, M.D.
Rheumatology Physician in North Bethesda, 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 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 · 193 beneficiaries · Rheumatology Physician avg: 2K
Generic prescribing
84%
generic claims · 14% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
89.8/100
▲ 7 pts above national avg 83.1 · Exceptional
Industry payments
$99.73
4 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
William Mullins, M.D. reported a CMS MIPS final score of 89.8/100 - above the 83.1 national average - and filed 1,291 Medicare Part D claims in 2023.
- 89.8/100
- MIPS score · +7 vs avg
- 1K
- Part D claims, 2023
- 84%
- 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.
William Mullins, 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
90 Top 42% higher than 58% 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 William Mullins, 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, William Mullins, M.D. writes more Part D claims than 34% of them and scores higher on MIPS quality than 60% - placing this provider in the lower-volume, high-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 William Mullins, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
✓
Board certification likely (heuristic, not verified)
William Mullins, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 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 Mullins, M.D.?
High performer (top quartile)Primary specialty
Rheumatology Physician
Medicare Part D claims
1,291 37% vs specialty avg
MIPS final score
89.8/100 6.7 pts vs avg
Specialty distribution in Maryland
How Rheumatology Physician compares to other specialties among Maryland providers
Medicare quality performance, MIPS
William Mullins, M.D.'s 2023 MIPS final score plotted against the Rheumatology Physician national average
- MIPS Final Score
- 89.8/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Rheumatology Physician) - 89.8/100 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).
William Mullins, M.D. appears in the CMS NPPES registry as a Rheumatology Physician provider holding M.D. credentials at 6001 MONTROSE RD, North Bethesda, MD, 20852, with a listed phone of (301) 230-5888. NPI 1518942184 was issued on 12/07/2005.
Medicare Part D records for calendar year 2023 show 1,291 prescription claims written by this provider, covering 193 Medicare beneficiaries and totaling roughly $1.6 million in drug spend, split 14% brand-name and 84% generic by claim count, with an opioid prescribing rate of 9.5%. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 89.8/100 for the 2023 performance year (Quality 81.5), 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 | 1518942184 |
|---|---|
| Specialty | Rheumatology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 12/07/2005 |
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
89.808
Final Score
Avg: 83.1
81.4692
Quality
100
Promoting Interoperability
Reporting: Individual
Hospital and facility affiliations
Facilities where William Mullins, 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.
Center For Rheumatic Diseases And Osteoporosis P.A.
Rockville, 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 Mullins, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$100
Largest payer
ABBVIE 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 Mullins, M.D. - brand share 14.0%
Rheumatology Physician average
14% brand-name claims vs 84% generic, on 1,291 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.
1,291
Total Claims
$1.6M
Total Drug Cost
193
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 2,964
- Total Day Supply
- 87,427
- Brand vs Generic
- 14% brand / 84% generic
- Brand Drug Cost
- $1.6M
- Generic Drug Cost
- $37K
- Opioid Claims
- 123 (9.5% rate)
Patient Demographics
- Average Patient Age
- 74.0 years
- Avg HCC Risk Score
- 1.22
- Gender Split
- 77% female / 23% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What William Mullins, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Methotrexate
Methotrexate
256 claims
- Prednisone
Prednisone
152 claims
- Tramadol Hcl 78
Tramadol Hcl
78 claims
- Leucovorin Calcium 68
Leucovorin Calcium
68 claims
- Meloxicam 55
Meloxicam
55 claims
- Enbrel 39
Enbrel
39 claims
- Enbrel Sureclick 36
Enbrel Sureclick
36 claims
- Alendronate Sodium 33
Alendronate Sodium
33 claims
| Drug | Claims |
|---|---|
| Methotrexate Methotrexate Sodium | 256 |
| Prednisone | 152 |
| Tramadol Hcl | 78 |
| Leucovorin Calcium | 68 |
| Meloxicam | 55 |
| Enbrel Etanercept | 39 |
| Enbrel Sureclick Etanercept | 36 |
| Alendronate Sodium | 33 |
| Gabapentin | 29 |
| Allopurinol | 26 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Rheumatology Physician Overview
How William Mullins, 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
William Mullins, M.D.'s 1,291 claims are below the specialty average of 2,054.
Nearby Rheumatology Physician Providers in Maryland
Other clinicians with the same primary specialty enrolled in Maryland, drawn from the same CMS NPPES roster as Mullins.
Dr. Jonathan Adelson
M.D.
Greenbelt, MD
Dr. Naila Ahmad
MD
Easton, MD
Dr. Grace Ahn
M.D.
Rockville, MD
Dr. Maria Alba-Dauhajre
MD
Silver Spring, MD
Dr. Jemima Felicity Albayda
MD
Baltimore, MD
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 Maryland 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 William Mullins, M.D.'s specialty? ▼
William Mullins, M.D. specializes in Rheumatology Physician and practices in North Bethesda, Maryland. Credentials: M.D..
How much does William Mullins, M.D. prescribe under Medicare Part D? ▼
In 2023, William Mullins, M.D. wrote 1,291 Medicare Part D claims totaling $1.6M in drug costs for 193 beneficiaries.
What is William Mullins, M.D.'s Medicare quality score? ▼
William Mullins, M.D. has a CMS MIPS Final Score of 89.8/100 (Quality: 81.5). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is William Mullins, M.D. located? ▼
William Mullins, M.D. is located at 6001 MONTROSE RD, North Bethesda, MD, 20852. Phone: (301) 230-5888.
What is William Mullins, M.D.'s NPI number? ▼
William Mullins, M.D.'s National Provider Identifier (NPI) is 1518942184, issued on 12/07/2005.
Does William Mullins, M.D. prescribe more brand-name or generic drugs? ▼
William Mullins, M.D.'s prescribing is 14% brand-name and 84% generic drugs by claim count, with $1.6M in brand drug costs.
Does William Mullins, M.D. prescribe opioids? ▼
Yes, William Mullins, M.D. had 123 opioid claims in 2023 with an opioid prescribing rate of 9.5%.
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 William Mullins, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, William Mullins, M.D.'s most frequently prescribed drugs include Methotrexate, Prednisone, Tramadol Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Mullins, M.D. accept Medicare? ▼
William Mullins, M.D. appears in CMS Medicare data with 1,291 Part D claims and 193 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Mullins, M.D.'s credentials? ▼
William Mullins, M.D.'s NPI is 1518942184 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.