2026 NPPES data Geriatric Psychiatry Physician NPI 1356440721 M.D.
Verify on CMS →

WILLIAM COOK, M.D.

Geriatric Psychiatry Physician in JACKSON, Mississippi. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
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)
What the federal data reveals: WILLIAM COOK, M.D. is a Geriatric Psychiatry Physician ([object Object]) practicing in JACKSON, Mississippi with a Medicare Part D prescribing footprint of 965 claims across 41 beneficiaries . Industry payments of $20.05 across 1 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: WILLIAM COOK, M.D. filed 965 Medicare Part D claims in 2023 across JACKSON, Mississippi. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

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).

WILLIAM COOK, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 09/22/2006

NPI 1356440721

Primary specialty

Geriatric Psychiatry Physician

Niche

785 US NPIs in this specialty

Medicare Part D claims

965 39% vs specialty avg

2023 prescription claims

Specialty avg: 1,586

Specialty distribution in Mississippi

How Geriatric Psychiatry Physician compares to other specialties among Mississippi providers

Mississippi providers

Geriatric Psychiatry Physician share within Mississippi

1. Geriatric Psychiatry Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Geriatric Psychiatry Physician share within Mississippi

Specialty board-certification context

Estimated specialty board-certified rate — Geriatric Psychiatry Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Geriatric Psychiatry Physician ABMS/AOA estimate

Est. board-certified rate (Geriatric Psychiatry Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Geriatric Psychiatry Physician) — ABMS / AOA estimate

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. is a Geriatric Psychiatry Physician provider practicing in JACKSON, Mississippi, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1356440721. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

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. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what COOK 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 965 prescription claims written by this provider, covering 41 Medicare beneficiaries and totaling roughly $47K 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.

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

4500 I 55 N
JACKSON, MS 39211

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.

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 →

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

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