William Merrell, M.D.
Specialist in Prescott Valley, Arizona. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 69,658 in Specialist, 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.
What the federal data shows
William Merrell, M.D. filed 1,016 Medicare Part D claims in 2023 as a Specialist in Prescott Valley, Arizona.
- 1K
- Part D claims, 2023
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 Merrell, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,016 Top 24% higher than 76% 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
What does the federal data show about William Merrell, M.D.?
Quality data not reportedPrimary specialty
Medicare Part D claims
Specialty distribution in Arizona
How Specialist compares to other specialties among Arizona providers
Largest specialties in Arizona (% of in-state providers)
Specialist ranks #37 among Arizona's specialties (0.8% of in-state providers)
Each bar is a specialty's share of the Arizona provider total, by primary NUCC taxonomy. The highlighted bar is Specialist; the long tail of smaller specialties is omitted for legibility.
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 Specialist. Verify directly:
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 Merrell, M.D. appears in the CMS NPPES registry as a Specialist provider holding M.D. credentials at 3221 N WINDSONG DR, Prescott Valley, AZ, 86314, with a listed phone of (928) 910-7010. NPI 1942339254 was issued on 03/04/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Merrell most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.
Medicare Part D records for calendar year 2023 show 1,016 prescription claims written by this provider, covering 181 Medicare beneficiaries and totaling roughly $92K in drug spend. These figures capture only Medicare Part D, commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.
Specialist is a high-volume specialty nationwide, with 69,658 enrolled providers across 55 states and an average of 1,474 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 | 1942339254 |
|---|---|
| Specialty | Specialist |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 03/04/2007 |
Verify this provider's license
PlainDoctor pulls this profile from the CMS NPPES public registry. Confirm William Merrell, M.D.'s current license status, disciplinary history, and board certifications with the Arizona Medical Board in Arizona before relying on this page for a clinical or care decision.
How we sourced this profile
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
Prescribing Breakdown
- 30-Day Fills
- 2,904
- Total Day Supply
- 86,872
- Generic Drug Cost
- $26K
Patient Demographics
- Average Patient Age
- 77.2 years
- Avg HCC Risk Score
- 1.00
- Gender Split
- 56% female / 44% 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 Merrell, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
97 claims
- Levothyroxine Sodium
Levothyroxine Sodium
68 claims
- Lisinopril
Lisinopril
66 claims
- Losartan Potassium
Losartan Potassium
64 claims
- Amlodipine Besylate
Amlodipine Besylate
61 claims
- Alendronate Sodium 30
Alendronate Sodium
30 claims
- Hydrochlorothiazide 26
Hydrochlorothiazide
26 claims
- Irbesartan 24
Irbesartan
24 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 97 |
| Levothyroxine Sodium | 68 |
| Lisinopril | 66 |
| Losartan Potassium | 64 |
| Amlodipine Besylate | 61 |
| Alendronate Sodium | 30 |
| Hydrochlorothiazide | 26 |
| Irbesartan | 24 |
| Simvastatin | 23 |
| Omeprazole | 22 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Specialist Overview
How William Merrell, M.D. fits within the Specialist landscape nationally.
William Merrell, M.D.'s 1,016 claims are below the specialty average of 1,474.
Nearby Specialist Providers in Arizona
Other clinicians with the same primary specialty enrolled in Arizona, drawn from the same CMS NPPES roster as Merrell.
Compare Specialist 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 Arizona medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Specialist 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
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Data Sources
- 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