2026 NPPES data Psychiatry Physician NPI 1366486961 MD
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BARBARA DIAZ HERNANDEZ, MD

Psychiatry Physician in HASTINGS, Michigan. 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
2K
Medicare Part D claims · 60 beneficiaries · Psychiatry Physician avg: 1K
Generic prescribing
87%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

BARBARA DIAZ HERNANDEZ, MD filed 1,877 Medicare Part D claims in 2023 as a Psychiatry Physician in HASTINGS, Michigan, prescribing 87% generic.

2K
Part D claims, 2023
87%
generic prescribing
Likely
board-certified (heuristic)

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.

BARBARA DIAZ HERNANDEZ, MD's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

1,877 Top 17% higher than 83% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). This entry sits in this band. 2,000–2,200: 213,991 prescribers (16%). Above this entry. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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 certification likely (heuristic — not verified)

BARBARA DIAZ HERNANDEZ, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about BARBARA DIAZ HERNANDEZ, MD?

Quality data not reported

NPI registry status

Active

Issued 06/15/2006

NPI 1366486961

Primary specialty

Psychiatry Physician

High-volume

53,104 US NPIs in this specialty

Medicare Part D claims

1,877 81% vs specialty avg

2023 prescription claims

Specialty avg: 1,038

Specialty distribution in Michigan

How Psychiatry Physician compares to other specialties among Michigan providers

Michigan providers

Psychiatry Physician share within Michigan

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

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).

BARBARA DIAZ HERNANDEZ, MD appears in the CMS NPPES registry as a Psychiatry Physician provider holding MD credentials at 500 BARFIELD DR, HASTINGS, MI, 49058, with a listed phone of (269) 948-8041. NPI 1366486961 was issued on 06/15/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DIAZ HERNANDEZ 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 1,877 prescription claims written by this provider, covering 60 Medicare beneficiaries and totaling roughly $471K in drug spend, split 13% brand-name and 87% 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

500 BARFIELD DR
HASTINGS, MI 49058

Provider Details

NPI 1366486961
Specialty Psychiatry Physician
Credentials MD
Gender Female
NPI Issued 06/15/2006

Hospital and facility affiliations

Facilities where BARBARA DIAZ HERNANDEZ, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

BARRY COUNTY COMMUNITY MENTAL HEALTH AUTHORITY
HASTINGS, MI

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

License & disciplinary context — Michigan MI-BOM 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~41K Michigan medical licensees in 2023 — they are NOT specific to BARBARA DIAZ HERNANDEZ, MD. To verify BARBARA DIAZ HERNANDEZ, MD's current license status, search the MI-BOM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

123
Total board actions, Michigan 2023
Across 120 cases
3.00
Actions per 1,000 licensees
Michigan statewide rate
probation
Most common action type
44 cases

MI-BOM publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Michigan disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

BARBARA DIAZ HERNANDEZ, MD — brand share 13.0%
Specialty average (est.)

13% brand-name claims vs 87% generic, on 1,877 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.

1,877
Total Claims
$471K
Total Drug Cost
60
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,913
Total Day Supply
50,637
Brand vs Generic
13% brand / 87% generic
Brand Drug Cost
$342K
Generic Drug Cost
$129K

Patient Demographics

Average Patient Age
49.1 years
Avg HCC Risk Score
1.34
Gender Split
58% female / 42% male

Top Prescribed Drugs (Medicare Part D)

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

What BARBARA DIAZ HERNANDEZ, MD prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Oxcarbazepine
162
Benztropine Mesylate
122
Vilazodone Hcl
109
Trazodone Hcl
104
Lurasidone Hcl
102
Escitalopram Oxalate
68
Prazosin Hcl
62
Paliperidone Er
Paliperidone
61
Vraylar
Cariprazine Hcl
60
Latuda
Lurasidone Hcl
58

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

Psychiatry Physician Overview

How BARBARA DIAZ HERNANDEZ, MD 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

BARBARA DIAZ HERNANDEZ, MD's 1,877 claims are above the specialty average of 1,038.

Nearby Psychiatry Physician Providers in Michigan

Other clinicians with the same primary specialty enrolled in Michigan, drawn from the same CMS NPPES roster as DIAZ HERNANDEZ.

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

Frequently Asked Questions

What is BARBARA DIAZ HERNANDEZ, MD's specialty?
BARBARA DIAZ HERNANDEZ, MD specializes in Psychiatry Physician and practices in HASTINGS, Michigan. Credentials: MD.
How much does BARBARA DIAZ HERNANDEZ, MD prescribe under Medicare Part D?
In 2023, BARBARA DIAZ HERNANDEZ, MD wrote 1,877 Medicare Part D claims totaling $471K in drug costs for 60 beneficiaries.
Where is BARBARA DIAZ HERNANDEZ, MD located?
BARBARA DIAZ HERNANDEZ, MD is located at 500 BARFIELD DR, HASTINGS, MI, 49058. Phone: (269) 948-8041.
What is BARBARA DIAZ HERNANDEZ, MD's NPI number?
BARBARA DIAZ HERNANDEZ, MD's National Provider Identifier (NPI) is 1366486961, issued on 06/15/2006.
Does BARBARA DIAZ HERNANDEZ, MD prescribe more brand-name or generic drugs?
BARBARA DIAZ HERNANDEZ, MD's prescribing is 13% brand-name and 87% generic drugs by claim count, with $342K 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 BARBARA DIAZ HERNANDEZ, MD prescribe most often?
Based on 2023 Medicare Part D data, BARBARA DIAZ HERNANDEZ, MD's most frequently prescribed drugs include Oxcarbazepine, Benztropine Mesylate, Vilazodone Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does BARBARA DIAZ HERNANDEZ, MD accept Medicare?
BARBARA DIAZ HERNANDEZ, MD appears in CMS Medicare data with 1,877 Part D claims and 60 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify BARBARA DIAZ HERNANDEZ, MD's credentials?
BARBARA DIAZ HERNANDEZ, MD's NPI is 1366486961 with credentials MD. 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