NPI registry status
Active
2026 NPPES data Geriatric Psychiatry Physician NPI 1356440721 M.D.
Verify on CMS → William Cook, M.D.
Geriatric Psychiatry Physician in Jackson, Mississippi.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 785 in Geriatric Psychiatry 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
965
Medicare Part D claims · 41 beneficiaries · Geriatric Psychiatry Physician avg: 2K
Industry payments
$20.05
1 payments · CMS Open Payments (Sunshine Act)
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
William Cook, M.D. filed 965 Medicare Part D claims in 2023 as a Geriatric Psychiatry Physician in Jackson, Mississippi.
- 965
- Part D claims, 2023
- $20.05
- 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 Cook, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
965 Top 25% higher than 75% 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
◑
Board-eligible specialty (heuristic, not verified)
William Cook, M.D. 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 Cook, M.D.?
Quality data not reportedPrimary specialty
Geriatric Psychiatry Physician
Medicare Part D claims
965 39% vs specialty avg
Specialty distribution in Mississippi
How Geriatric Psychiatry Physician compares to other specialties among Mississippi 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 Geriatric Psychiatry 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 Cook, M.D. appears in the CMS NPPES registry as a Geriatric Psychiatry Physician provider holding M.D. credentials at 4500 I 55 N, Jackson, MS, 39211, with a listed phone of (601) 366-3660. NPI 1356440721 was issued on 09/22/2006.
Medicare Part D records for calendar year 2023 show 965 prescription claims written by this provider, covering 41 Medicare beneficiaries and totaling roughly $47K in drug spend.
Geriatric Psychiatry Physician is a narrow specialty nationwide, with 785 enrolled providers across 46 states and an average of 1,586 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 | 1356440721 |
|---|---|
| Specialty | Geriatric Psychiatry Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 09/22/2006 |
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 Cook, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$20
Largest payer
ABIOMED
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.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
965
Total Claims
$47K
Total Drug Cost
41
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,111
- Total Day Supply
- 32,809
- Generic Drug Cost
- $25K
Patient Demographics
- Average Patient Age
- 69.4 years
- Avg HCC Risk Score
- 0.94
- Gender Split
- 61% female / 39% 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 Cook, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Clonazepam
Clonazepam
125 claims
- Alprazolam
Alprazolam
76 claims
- Duloxetine Hcl
Duloxetine Hcl
50 claims
- Dextroamphetamine-… 45
Dextroamphetamine-Amphetamine
45 claims
- Lamotrigine 44
Lamotrigine
44 claims
- Bupropion Xl 41
Bupropion Xl
41 claims
- Gabapentin 41
Gabapentin
41 claims
- Fluoxetine Hcl 38
Fluoxetine Hcl
38 claims
| Drug | Claims |
|---|---|
| Clonazepam | 125 |
| Alprazolam | 76 |
| Duloxetine Hcl | 50 |
| Dextroamphetamine-Amphetamine Dextroamphetamine/Amphetamine | 45 |
| Lamotrigine | 44 |
| Bupropion Xl Bupropion Hcl | 41 |
| Gabapentin | 41 |
| Fluoxetine Hcl | 38 |
| Trazodone Hcl | 34 |
| Venlafaxine Hcl Er Venlafaxine Hcl | 33 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Geriatric Psychiatry Physician Overview
How William Cook, M.D. fits within the Geriatric Psychiatry Physician landscape nationally.
785
Geriatric Psychiatry Physician Providers in US
46
States with Geriatric Psychiatry Physician
1,586
Avg Claims per Provider
William Cook, M.D.'s 965 claims are below the specialty average of 1,586.
Nearby Geriatric Psychiatry Physician Providers in Mississippi
Other clinicians with the same primary specialty enrolled in Mississippi, drawn from the same CMS NPPES roster as Cook.
Compare Geriatric Psychiatry 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 Mississippi medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Geriatric Psychiatry 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 Cook, M.D.'s specialty? ▼
William Cook, M.D. specializes in Geriatric Psychiatry Physician and practices in Jackson, Mississippi. Credentials: M.D..
How much does William Cook, M.D. prescribe under Medicare Part D? ▼
In 2023, William Cook, M.D. wrote 965 Medicare Part D claims totaling $47K in drug costs for 41 beneficiaries.
Where is William Cook, M.D. located? ▼
William Cook, M.D. is located at 4500 I 55 N, Jackson, MS, 39211. Phone: (601) 366-3660.
What is William Cook, M.D.'s NPI number? ▼
William Cook, M.D.'s National Provider Identifier (NPI) is 1356440721, issued on 09/22/2006.
How many Geriatric Psychiatry Physician providers are there in the US? ▼
There are 785 Geriatric Psychiatry Physician providers across 46 states in the US. The average Geriatric Psychiatry Physician provider writes 1,586 Medicare Part D claims per year.
What drugs does William Cook, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, William Cook, M.D.'s most frequently prescribed drugs include Clonazepam, Alprazolam, Duloxetine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Cook, M.D. accept Medicare? ▼
William Cook, M.D. appears in CMS Medicare data with 965 Part D claims and 41 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Cook, M.D.'s credentials? ▼
William Cook, M.D.'s NPI is 1356440721 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
Compiled from official public sources by the PlainDoctor editorial team.