NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1861883563
Verify on CMS → William Aitken
Internal Medicine Physician in Memphis, Tennessee.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 172,858 in 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
113
Medicare Part D claims · 13 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
77%
generic claims · 23% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$343.68
11 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 Aitken filed 113 Medicare Part D claims in 2023 as a Internal Medicine Physician in Memphis, Tennessee, prescribing 77% generic.
- 113
- Part D claims, 2023
- 77%
- generic prescribing
- $343.68
- industry payments (Sunshine Act)
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 Aitken's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
113 35th percentile higher than 35% 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
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Board-eligible specialty (heuristic, not verified)
William Aitken practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about William Aitken?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
113 96% vs specialty avg
Specialty distribution in Tennessee
How Internal Medicine Physician compares to other specialties among Tennessee 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 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).
William Aitken appears in the CMS NPPES registry as a Internal Medicine Physician provider at 1211 UNION AVE STE 965, Memphis, TN, 38104, with a listed phone of (901) 435-8550. NPI 1861883563 was issued on 02/17/2015.
Medicare Part D records for calendar year 2023 show 113 prescription claims written by this provider, covering 13 Medicare beneficiaries and totaling roughly $27K in drug spend, split 23% brand-name and 77% generic by claim count.
Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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 | 1861883563 |
|---|---|
| Specialty | Internal Medicine Physician |
| Gender | Male |
| NPI Issued | 02/17/2015 |
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 Aitken. Source: openpaymentsdata.cms.gov.
Total received
$344
Largest payer
Medtronic, 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 Aitken - brand share 23.0%
Internal Medicine Physician average
23% brand-name claims vs 77% generic, on 113 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.
113
Total Claims
$27K
Total Drug Cost
13
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 238
- Total Day Supply
- 7,140
- Brand vs Generic
- 23% brand / 77% generic
- Brand Drug Cost
- $26K
- Generic Drug Cost
- $1K
Patient Demographics
- Average Patient Age
- 66.8 years
- Avg HCC Risk Score
- 1.93
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What William Aitken prescribes most
Top Medicare Part D drugs by claim count, 2023
- Farxiga
Farxiga
13 claims
- Carvedilol
Carvedilol
12 claims
- Amlodipine Besylate
Amlodipine Besylate
11 claims
| Drug | Claims |
|---|---|
| Farxiga Dapagliflozin Propanediol | 13 |
| Carvedilol | 12 |
| Amlodipine Besylate | 11 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How William Aitken fits within the Internal Medicine Physician landscape nationally.
172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider
William Aitken's 113 claims are below the specialty average of 2,716.
Nearby Internal Medicine Physician Providers in Tennessee
Other clinicians with the same primary specialty enrolled in Tennessee, drawn from the same CMS NPPES roster as Aitken.
Dr. Damon Abaray
MD
Nashville, TN
Dr. Samuel Abbas
MD
Hixson, TN
Dr. Matthew Abbate
MD
Nashville, TN
Dr. Kazeen Abdullah
M.D.
Smyrna, TN
Dr. Sarmed Abdullah
M.D.
Lexington, TN
Compare Internal Medicine 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 Tennessee medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Internal Medicine 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 Aitken's specialty? ▼
William Aitken specializes in Internal Medicine Physician and practices in Memphis, Tennessee.
How much does William Aitken prescribe under Medicare Part D? ▼
In 2023, William Aitken wrote 113 Medicare Part D claims totaling $27K in drug costs for 13 beneficiaries.
Where is William Aitken located? ▼
William Aitken is located at 1211 UNION AVE STE 965, Memphis, TN, 38104. Phone: (901) 435-8550.
What is William Aitken's NPI number? ▼
William Aitken's National Provider Identifier (NPI) is 1861883563, issued on 02/17/2015.
Does William Aitken prescribe more brand-name or generic drugs? ▼
William Aitken's prescribing is 23% brand-name and 77% generic drugs by claim count, with $26K in brand drug costs.
How many Internal Medicine Physician providers are there in the US? ▼
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does William Aitken prescribe most often? ▼
Based on 2023 Medicare Part D data, William Aitken's most frequently prescribed drugs include Farxiga, Carvedilol, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Aitken accept Medicare? ▼
William Aitken appears in CMS Medicare data with 113 Part D claims and 13 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Aitken's credentials? ▼
William Aitken's NPI is 1861883563. 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.