2026 NPPES data Hospitalist Physician NPI 1275162778 M.D., M.P.H.
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DAYOUNG RYU, M.D., M.P.H.

Hospitalist Physician in NEW HAVEN, Connecticut. 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
30
Medicare Part D claims · Hospitalist Physician avg: 888
Industry payments
$45.43
2 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

DAYOUNG RYU, M.D., M.P.H. filed 30 Medicare Part D claims in 2023 as a Hospitalist Physician in NEW HAVEN, Connecticut.

30
Part D claims, 2023
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.

DAYOUNG RYU, M.D., M.P.H.'s Medicare Part D volume vs every U.S. prescriber

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

30 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 certification likely (heuristic — not verified)

DAYOUNG RYU, M.D., M.P.H. 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 DAYOUNG RYU, M.D., M.P.H.?

Quality data not reported

NPI registry status

Active

Issued 04/06/2020

NPI 1275162778

Primary specialty

Hospitalist Physician

Mid-sized

16,825 US NPIs in this specialty

Medicare Part D claims

30 97% vs specialty avg

2023 prescription claims

Specialty avg: 888

Specialty distribution in Connecticut

How Hospitalist Physician compares to other specialties among Connecticut providers

Connecticut providers

Hospitalist Physician share within Connecticut

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

Specialty board-certification context

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

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

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

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

DAYOUNG RYU, M.D., M.P.H. appears in the CMS NPPES registry as a Hospitalist Physician provider holding M.D., M.P.H. credentials at 20 YORK STREET, NEW HAVEN, CT, 06510, with a listed phone of (203) 688-1734. NPI 1275162778 was issued on 04/06/2020. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what RYU 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 30 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $862 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.

Hospitalist Physician is a mid-sized specialty nationwide, with 16,825 enrolled providers across 54 states and an average of 888 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

20 YORK STREET
NEW HAVEN, CT 06510

Provider Details

NPI 1275162778
Specialty Hospitalist Physician
Credentials M.D., M.P.H.
Gender Female
NPI Issued 04/06/2020

Hospital and facility affiliations

Facilities where DAYOUNG RYU, M.D., M.P.H. 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.

NORTHEAST MEDICAL GROUP INC
NEW HAVEN, CT

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

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 DAYOUNG RYU, M.D., M.P.H.. Source: openpaymentsdata.cms.gov.

Total received

$45

Largest payer

Novartis Pharmaceuticals Corporation

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.

30
Total Claims
$862
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
33
Total Day Supply
760
Generic Drug Cost
$818

Patient Demographics

Average Patient Age
71.3 years
Avg HCC Risk Score
1.88

Hospitalist Physician Overview

How DAYOUNG RYU, M.D., M.P.H. fits within the Hospitalist Physician landscape nationally.

16,825
Hospitalist Physician Providers in US
54
States with Hospitalist Physician
888
Avg Claims per Provider

DAYOUNG RYU, M.D., M.P.H.'s 30 claims are below the specialty average of 888.

Nearby Hospitalist Physician Providers in Connecticut

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

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

Frequently Asked Questions

What is DAYOUNG RYU, M.D., M.P.H.'s specialty?
DAYOUNG RYU, M.D., M.P.H. specializes in Hospitalist Physician and practices in NEW HAVEN, Connecticut. Credentials: M.D., M.P.H..
How much does DAYOUNG RYU, M.D., M.P.H. prescribe under Medicare Part D?
In 2023, DAYOUNG RYU, M.D., M.P.H. wrote 30 Medicare Part D claims totaling $862 in drug costs for N/A beneficiaries.
Where is DAYOUNG RYU, M.D., M.P.H. located?
DAYOUNG RYU, M.D., M.P.H. is located at 20 YORK STREET, NEW HAVEN, CT, 06510. Phone: (203) 688-1734.
What is DAYOUNG RYU, M.D., M.P.H.'s NPI number?
DAYOUNG RYU, M.D., M.P.H.'s National Provider Identifier (NPI) is 1275162778, issued on 04/06/2020.
How many Hospitalist Physician providers are there in the US?
There are 16,825 Hospitalist Physician providers across 54 states in the US. The average Hospitalist Physician provider writes 888 Medicare Part D claims per year.
Does DAYOUNG RYU, M.D., M.P.H. accept Medicare?
DAYOUNG RYU, M.D., M.P.H. appears in CMS Medicare data with 30 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 DAYOUNG RYU, M.D., M.P.H.'s credentials?
DAYOUNG RYU, M.D., M.P.H.'s NPI is 1275162778 with credentials M.D., M.P.H.. 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