2026 NPPES data Specialist NPI 1437127966 M.D.
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Maria Diaz, M.D.

Specialist in Baltimore, Maryland. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 69,658 in Specialist, 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
185
Medicare Part D claims · Specialist avg: 1K
Generic prescribing
77%
generic claims · 16% brand-name · higher generic rates reduce patient out-of-pocket costs
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Maria Diaz, M.D. filed 185 Medicare Part D claims in 2023 as a Specialist in Baltimore, Maryland, prescribing 77% generic.

185
Part D claims, 2023
77%
generic prescribing

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.

Maria Diaz, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

185 35th percentile higher than 35% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2K+: 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

What does the federal data show about Maria Diaz, M.D.?

Quality data not reported

NPI registry status

Active

Issued 03/10/2006

NPI 1437127966

Primary specialty

Specialist

High-volume

69,658 US NPIs in this specialty

Medicare Part D claims

185 87% vs specialty avg

2023 prescription claims

Specialty avg: 1,474

Specialty distribution in Maryland

How Specialist compares to other specialties among Maryland providers

Maryland providers
Behavior Technician - 14.1%Behavior Technician14.1%Clinical Social Worker - 5.5%Clinical Social Worker5.5%Student in an Organized Health Care Education/Training Program - 4.5%Student in an Organized Health Care Education/Training Program4.5%Home Health Aide - 4.4%Home Health Aide4.4%Physical Therapist - 3.9%Physical Therapist3.9%Pharmacist - 3.6%Pharmacist3.6%Specialist - 0.7%Specialist0.7%
Largest specialties in Maryland (% of in-state 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 Specialist. Verify directly:

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).

Maria Diaz, M.D. appears in the CMS NPPES registry as a Specialist provider holding M.D. credentials at 6 VOLZ AVE, Baltimore, MD, 21220, with a listed phone of (410) 687-2118. NPI 1437127966 was issued on 03/10/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Diaz 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 185 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $15K in drug spend, split 16% brand-name and 77% 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.

Specialist is a high-volume specialty nationwide, with 69,658 enrolled providers across 55 states and an average of 1,474 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

6 VOLZ AVE
Baltimore, MD 21220

Provider Details

NPI 1437127966
Specialty Specialist
Credentials M.D.
Gender Female
NPI Issued 03/10/2006

Brand vs generic prescribing mix · Typical

Maria Diaz, M.D. - brand share 16.0%
Specialist average

16% brand-name claims vs 77% generic, on 185 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.

185
Total Claims
$15K
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
185
Total Day Supply
5,308
Brand vs Generic
16% brand / 77% generic
Brand Drug Cost
$9K
Generic Drug Cost
$4K

Patient Demographics

Average Patient Age
81.6 years
Avg HCC Risk Score
1.26

Top Prescribed Drugs (Medicare Part D)

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

What Maria Diaz, M.D. 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
Omeprazole
18
Losartan Potassium
13
Olanzapine
13
Pravastatin Sodium
13
Jardiance
Empagliflozin
12
Metformin Er Gastric
Metformin Hcl
12
Clopidogrel
Clopidogrel Bisulfate
11
Tresiba Flextouch U-100
Insulin Degludec
11
Autoshield Duo Pen Needle
"Pen Needle
N/A

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

Specialist Overview

How Maria Diaz, M.D. fits within the Specialist landscape nationally.

69,658
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider

Maria Diaz, M.D.'s 185 claims are below the specialty average of 1,474.

Nearby Specialist Providers in Maryland

Other clinicians with the same primary specialty enrolled in Maryland, drawn from the same CMS NPPES roster as Diaz.

Compare Specialist 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 Maryland medical board, federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Specialist 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.

Frequently Asked Questions

What is Maria Diaz, M.D.'s specialty?
Maria Diaz, M.D. specializes in Specialist and practices in Baltimore, Maryland. Credentials: M.D..
How much does Maria Diaz, M.D. prescribe under Medicare Part D?
In 2023, Maria Diaz, M.D. wrote 185 Medicare Part D claims totaling $15K in drug costs for N/A beneficiaries.
Where is Maria Diaz, M.D. located?
Maria Diaz, M.D. is located at 6 VOLZ AVE, Baltimore, MD, 21220. Phone: (410) 687-2118.
What is Maria Diaz, M.D.'s NPI number?
Maria Diaz, M.D.'s National Provider Identifier (NPI) is 1437127966, issued on 03/10/2006.
Does Maria Diaz, M.D. prescribe more brand-name or generic drugs?
Maria Diaz, M.D.'s prescribing is 16% brand-name and 77% generic drugs by claim count, with $9K in brand drug costs.
How many Specialist providers are there in the US?
There are 69,658 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does Maria Diaz, M.D. prescribe most often?
Based on 2023 Medicare Part D data, Maria Diaz, M.D.'s most frequently prescribed drugs include Omeprazole, Losartan Potassium, Olanzapine. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Maria Diaz, M.D. accept Medicare?
Maria Diaz, M.D. appears in CMS Medicare data with 185 Part D claims and N/A Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Maria Diaz, M.D.'s credentials?
Maria Diaz, M.D.'s NPI is 1437127966 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

Compiled from official public sources by the PlainDoctor editorial team.