2026 NPPES data Psychiatry Physician NPI 1013055706 M.D.
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TAMMY CHEN, M.D.

Psychiatry Physician in ROCK HILL, South Carolina. 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
5K
Medicare Part D claims · 203 beneficiaries · Psychiatry Physician avg: 1K
Generic prescribing
88%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$940.87
51 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: TAMMY CHEN, M.D. is a Psychiatry Physician ([object Object]) practicing in ROCK HILL, South Carolina with a Medicare Part D prescribing footprint of 5K claims across 203 beneficiaries — 12% brand-name prescribing . Industry payments of $940.87 across 51 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: TAMMY CHEN, M.D. filed 4,521 Medicare Part D claims in 2023 across ROCK HILL, South Carolina. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

TAMMY CHEN, 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).

TAMMY CHEN, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 02/02/2007

NPI 1013055706

Primary specialty

Psychiatry Physician

High-volume

53,104 US NPIs in this specialty

Medicare Part D claims

4,521 336% vs specialty avg

2023 prescription claims

Specialty avg: 1,038

Specialty distribution in South Carolina

How Psychiatry Physician compares to other specialties among South Carolina providers

South Carolina providers

Psychiatry Physician share within South Carolina

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (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).

TAMMY CHEN, M.D. is a Psychiatry Physician provider practicing in ROCK HILL, South Carolina, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1013055706. 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.

TAMMY CHEN, M.D. appears in the CMS NPPES registry as a Psychiatry Physician provider holding M.D. credentials at 2424 INDIA HOOK RD, ROCK HILL, SC, 29732, with a listed phone of (803) 328-8255. NPI 1013055706 was issued on 02/02/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHEN 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 4,521 prescription claims written by this provider, covering 203 Medicare beneficiaries and totaling roughly $765K in drug spend, split 12% brand-name and 88% generic by claim count. 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.

Psychiatry Physician is a high-volume specialty nationwide, with 53,104 enrolled providers across 56 states and an average of 1,038 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

2424 INDIA HOOK RD
ROCK HILL, SC 29732

Provider Details

NPI 1013055706
Specialty Psychiatry Physician
Credentials M.D.
Gender Female
NPI Issued 02/02/2007

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 TAMMY CHEN, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$941

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

TAMMY CHEN, M.D. — brand share 12.0%
Specialty average (est.)

12% brand-name claims vs 88% generic, on 4,521 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.

4,521
Total Claims
$765K
Total Drug Cost
203
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
6,347
Total Day Supply
189,105
Brand vs Generic
12% brand / 88% generic
Brand Drug Cost
$613K
Generic Drug Cost
$152K

Patient Demographics

Average Patient Age
64.7 years
Avg HCC Risk Score
1.42
Gender Split
78% female / 22% male
Age Distribution
<65: 82, 65-74: 82, 75-84: N/A, 85+: N/A

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Alprazolam
571
Clonazepam
404
Dextroamphetamine-Amphetamine
Dextroamphetamine/Amphetamine
298
Trazodone Hcl
268
Fluoxetine Hcl
204
Lorazepam
190
Zolpidem Tartrate
138
Venlafaxine Hcl Er
Venlafaxine Hcl
137
Vraylar
Cariprazine Hcl
107
Bupropion Xl
Bupropion Hcl
106

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Psychiatry Physician Overview

How TAMMY CHEN, M.D. fits within the Psychiatry Physician landscape nationally.

53,104
Psychiatry Physician Providers in US
56
States with Psychiatry Physician
1,038
Avg Claims per Provider

TAMMY CHEN, M.D.'s 4,521 claims are above the specialty average of 1,038.

Nearby Psychiatry Physician Providers in South Carolina

Other clinicians with the same primary specialty enrolled in South Carolina, drawn from the same CMS NPPES roster as CHEN.

Compare Psychiatry Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is TAMMY CHEN, M.D.'s specialty?
TAMMY CHEN, M.D. specializes in Psychiatry Physician and practices in ROCK HILL, South Carolina. Credentials: M.D..
How much does TAMMY CHEN, M.D. prescribe under Medicare Part D?
In 2023, TAMMY CHEN, M.D. wrote 4,521 Medicare Part D claims totaling $765K in drug costs for 203 beneficiaries.
Where is TAMMY CHEN, M.D. located?
TAMMY CHEN, M.D. is located at 2424 INDIA HOOK RD, ROCK HILL, SC, 29732. Phone: (803) 328-8255.
What is TAMMY CHEN, M.D.'s NPI number?
TAMMY CHEN, M.D.'s National Provider Identifier (NPI) is 1013055706, issued on 02/02/2007.
Does TAMMY CHEN, M.D. prescribe more brand-name or generic drugs?
TAMMY CHEN, M.D.'s prescribing is 12% brand-name and 88% generic drugs by claim count, with $613K in brand drug costs.
How many Psychiatry Physician providers are there in the US?
There are 53,104 Psychiatry Physician providers across 56 states in the US. The average Psychiatry Physician provider writes 1,038 Medicare Part D claims per year.
What drugs does TAMMY CHEN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, TAMMY CHEN, M.D.'s most frequently prescribed drugs include Alprazolam, Clonazepam, Dextroamphetamine-Amphetamine. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does TAMMY CHEN, M.D. accept Medicare?
TAMMY CHEN, M.D. appears in CMS Medicare data with 4,521 Part D claims and 203 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify TAMMY CHEN, M.D.'s credentials?
TAMMY CHEN, M.D.'s NPI is 1013055706 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