2026 NPPES data Obstetrics & Gynecology Physician NPI 1265739668 M.D.
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RONALD DIENER, M.D.

Obstetrics & Gynecology Physician in PIKESVILLE, Maryland. 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
43
Medicare Part D claims · Obstetrics & Gynecology Physician avg: 179

What the federal data shows

RONALD DIENER, M.D. filed 43 Medicare Part D claims in 2023 as a Obstetrics & Gynecology Physician in PIKESVILLE, Maryland.

43
Part D claims, 2023

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.

RONALD DIENER, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

43 0th percentile higher than 0% 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. 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-eligible specialty (heuristic — not verified)

RONALD DIENER, 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 RONALD DIENER, M.D.?

Quality data not reported

NPI registry status

Active

Issued 02/21/2011

NPI 1265739668

Primary specialty

Obstetrics & Gynecology Physician

Mid-sized

44,313 US NPIs in this specialty

Medicare Part D claims

43 76% vs specialty avg

2023 prescription claims

Specialty avg: 179

Specialty distribution in Maryland

How Obstetrics & Gynecology Physician compares to other specialties among Maryland providers

Maryland providers

Obstetrics & Gynecology Physician share within Maryland

1. Obstetrics & Gynecology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Obstetrics & Gynecology Physician share within Maryland

Specialty board-certification context

Estimated specialty board-certified rate — Obstetrics & Gynecology Physician (ABMS / AOA reference)

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

Est. board-certified rate (Obstetrics & Gynecology Physician) — ABMS / AOA estimate

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

RONALD DIENER, M.D. appears in the CMS NPPES registry as a Obstetrics & Gynecology Physician provider holding M.D. credentials at 10 GLENCLIFFE CIR, PIKESVILLE, MD, 21208, with a listed phone of (410) 296-7090. NPI 1265739668 was issued on 02/21/2011. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DIENER 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 43 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $2K 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.

Obstetrics & Gynecology Physician is a mid-sized specialty nationwide, with 44,313 enrolled providers across 56 states and an average of 179 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

10 GLENCLIFFE CIR
PIKESVILLE, MD 21208

Provider Details

NPI 1265739668
Specialty Obstetrics & Gynecology Physician
Credentials M.D.
Gender Male
NPI Issued 02/21/2011

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

43
Total Claims
$2K
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
111
Total Day Supply
3,283
Generic Drug Cost
$1K

Patient Demographics

Average Patient Age
78.7 years
Avg HCC Risk Score
1.01

Obstetrics & Gynecology Physician Overview

How RONALD DIENER, M.D. fits within the Obstetrics & Gynecology Physician landscape nationally.

44,313
Obstetrics & Gynecology Physician Providers in US
56
States with Obstetrics & Gynecology Physician
179
Avg Claims per Provider

RONALD DIENER, M.D.'s 43 claims are below the specialty average of 179.

Nearby Obstetrics & Gynecology Physician Providers in Maryland

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

Compare Obstetrics & Gynecology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is RONALD DIENER, M.D.'s specialty?
RONALD DIENER, M.D. specializes in Obstetrics & Gynecology Physician and practices in PIKESVILLE, Maryland. Credentials: M.D..
How much does RONALD DIENER, M.D. prescribe under Medicare Part D?
In 2023, RONALD DIENER, M.D. wrote 43 Medicare Part D claims totaling $2K in drug costs for N/A beneficiaries.
Where is RONALD DIENER, M.D. located?
RONALD DIENER, M.D. is located at 10 GLENCLIFFE CIR, PIKESVILLE, MD, 21208. Phone: (410) 296-7090.
What is RONALD DIENER, M.D.'s NPI number?
RONALD DIENER, M.D.'s National Provider Identifier (NPI) is 1265739668, issued on 02/21/2011.
How many Obstetrics & Gynecology Physician providers are there in the US?
There are 44,313 Obstetrics & Gynecology Physician providers across 56 states in the US. The average Obstetrics & Gynecology Physician provider writes 179 Medicare Part D claims per year.
Does RONALD DIENER, M.D. accept Medicare?
RONALD DIENER, M.D. appears in CMS Medicare data with 43 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 RONALD DIENER, M.D.'s credentials?
RONALD DIENER, M.D.'s NPI is 1265739668 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