2026 NPPES data Cardiovascular Disease Physician NPI 1851397467 M.D.
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STEPHEN DAY, M.D.

Cardiovascular Disease Physician in ALEXANDRIA, Virginia. 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
1K
Medicare Part D claims · 238 beneficiaries · Cardiovascular Disease Physician avg: 3K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
81.283/100
▼ 2 pts below national avg 83.1 · [object Object]
Industry payments
$307.48
16 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: STEPHEN DAY, M.D. is a Cardiovascular Disease Physician ([object Object]) practicing in ALEXANDRIA, Virginia with a Medicare Part D prescribing footprint of 1K claims across 238 beneficiaries — 11% brand-name prescribing . Their CMS MIPS Final Score of 81.283/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $307.48 across 16 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: STEPHEN DAY, M.D. reported a CMS MIPS final score of 81.283 out of 100, below the 83.1 national average, and filed 1,393 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

STEPHEN DAY, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

STEPHEN DAY, M.D. at a glance

Near national average

NPI registry status

Active

Issued 06/28/2005

NPI 1851397467

Primary specialty

Cardiovascular Disease Physician

Mid-sized

24,795 US NPIs in this specialty

Medicare Part D claims

1,393 54% vs specialty avg

2023 prescription claims

Specialty avg: 3,033

MIPS final score

81.283/100 1.816999999999993% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in Virginia

How Cardiovascular Disease Physician compares to other specialties among Virginia providers

Virginia providers

Cardiovascular Disease Physician share within Virginia

1. Cardiovascular Disease Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Cardiovascular Disease Physician share within Virginia

Medicare quality performance — MIPS

STEPHEN DAY, M.D.'s 2023 MIPS final score plotted against the Cardiovascular Disease Physician national average

Near national average
MIPS Final Score
81.283/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Cardiovascular Disease Physician) — 81.283/100 vs national avg 83.1

0%100%National avg83%81.3%
MIPS final score (Cardiovascular Disease Physician) — 81.283/100 vs national avg 83.1

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).

STEPHEN DAY, M.D. is a Cardiovascular Disease Physician provider practicing in ALEXANDRIA, Virginia, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1851397467. 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.

STEPHEN DAY, M.D. appears in the CMS NPPES registry as a Cardiovascular Disease Physician provider holding M.D. credentials at 4825 MARK CENTER DR STE 150, ALEXANDRIA, VA, 22311, with a listed phone of (703) 751-8111. NPI 1851397467 was issued on 06/28/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DAY 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 1,393 prescription claims written by this provider, covering 238 Medicare beneficiaries and totaling roughly $210K in drug spend, split 11% brand-name and 89% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 81.283/100 for the 2023 performance year (Quality 70.77, Cost 66.84), compared with the national average of 83.1.

Cardiovascular Disease Physician is a mid-sized specialty nationwide, with 24,795 enrolled providers across 54 states and an average of 3,033 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

4825 MARK CENTER DR STE 150
ALEXANDRIA, VA 22311

Provider Details

NPI 1851397467
Specialty Cardiovascular Disease Physician
Credentials M.D.
Gender Male
NPI Issued 06/28/2005

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

81.283
Final Score
Avg: 83.1
70.77
Quality
66.84
Cost
100
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where STEPHEN DAY, M.D. 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.

INOVA HEALTH CARE SERVICES
ARLINGTON, VA

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 STEPHEN DAY, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$307

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.

Brand vs generic prescribing mix · Typical

STEPHEN DAY, M.D. — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 1,393 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.

1,393
Total Claims
$210K
Total Drug Cost
238
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
3,839
Total Day Supply
114,562
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$176K
Generic Drug Cost
$34K

Patient Demographics

Average Patient Age
75.1 years
Avg HCC Risk Score
1.38
Gender Split
44% female / 56% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Atorvastatin Calcium
179
Metoprolol Succinate
144
Eliquis
Apixaban
78
Amlodipine Besylate
71
Rosuvastatin Calcium
68
Lisinopril
67
Furosemide
66
Losartan Potassium
65
Carvedilol
55
Clopidogrel
Clopidogrel Bisulfate
55

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

Cardiovascular Disease Physician Overview

How STEPHEN DAY, M.D. fits within the Cardiovascular Disease Physician landscape nationally.

24,795
Cardiovascular Disease Physician Providers in US
54
States with Cardiovascular Disease Physician
3,033
Avg Claims per Provider

STEPHEN DAY, M.D.'s 1,393 claims are below the specialty average of 3,033.

Nearby Cardiovascular Disease Physician Providers in Virginia

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

Compare Cardiovascular Disease Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is STEPHEN DAY, M.D.'s specialty?
STEPHEN DAY, M.D. specializes in Cardiovascular Disease Physician and practices in ALEXANDRIA, Virginia. Credentials: M.D..
How much does STEPHEN DAY, M.D. prescribe under Medicare Part D?
In 2023, STEPHEN DAY, M.D. wrote 1,393 Medicare Part D claims totaling $210K in drug costs for 238 beneficiaries.
What is STEPHEN DAY, M.D.'s Medicare quality score?
STEPHEN DAY, M.D. has a CMS MIPS Final Score of 81.283/100 (Quality: 70.77, Cost: 66.84). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is STEPHEN DAY, M.D. located?
STEPHEN DAY, M.D. is located at 4825 MARK CENTER DR STE 150, ALEXANDRIA, VA, 22311. Phone: (703) 751-8111.
What is STEPHEN DAY, M.D.'s NPI number?
STEPHEN DAY, M.D.'s National Provider Identifier (NPI) is 1851397467, issued on 06/28/2005.
Does STEPHEN DAY, M.D. prescribe more brand-name or generic drugs?
STEPHEN DAY, M.D.'s prescribing is 11% brand-name and 89% generic drugs by claim count, with $176K in brand drug costs.
How many Cardiovascular Disease Physician providers are there in the US?
There are 24,795 Cardiovascular Disease Physician providers across 54 states in the US. The average Cardiovascular Disease Physician provider writes 3,033 Medicare Part D claims per year.
What drugs does STEPHEN DAY, M.D. prescribe most often?
Based on 2023 Medicare Part D data, STEPHEN DAY, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Metoprolol Succinate, Eliquis. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does STEPHEN DAY, M.D. accept Medicare?
STEPHEN DAY, M.D. appears in CMS Medicare data with 1,393 Part D claims and 238 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify STEPHEN DAY, M.D.'s credentials?
STEPHEN DAY, M.D.'s NPI is 1851397467 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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