2026 NPPES data Cardiovascular Disease Physician NPI 1447238324 M.D.
Verify on CMS →

CATHLEEN BAIREY MERZ, M.D.

Cardiovascular Disease Physician in LOS ANGELES, California. 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
555
Medicare Part D claims · 149 beneficiaries · Cardiovascular Disease Physician avg: 3K
Generic prescribing
90%
generic claims · 10% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
87.6775/100
▲ 5 pts above national avg 83.1 · [object Object]
Industry payments
$223.9K
34 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

CATHLEEN BAIREY MERZ, M.D. reported a CMS MIPS final score of 87.6775/100 — above the 83.1 national average — and filed 555 Medicare Part D claims in 2023.

87.6775/100
MIPS score · +5 vs avg
555
Part D claims, 2023
90%
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.

CATHLEEN BAIREY MERZ, M.D.'s MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

88 Top 46% higher than 54% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). Below this entry. 80–90: 129,887 scored providers (27%). This entry sits in this band. 90–100: 189,403 scored providers (40%). Above this entry. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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 Merit-based Incentive Payment System (MIPS) · 2023

Board certification likely (heuristic — not verified)

CATHLEEN BAIREY MERZ, 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).

What does the federal data show about CATHLEEN BAIREY MERZ, M.D.?

High performer (top quartile)

NPI registry status

Active

Issued 01/03/2006

NPI 1447238324

Primary specialty

Cardiovascular Disease Physician

Mid-sized

24,795 US NPIs in this specialty

Medicare Part D claims

555 82% vs specialty avg

2023 prescription claims

Specialty avg: 3,033

MIPS final score

87.6775/100 4.577500000000001% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in California

How Cardiovascular Disease Physician compares to other specialties among California providers

California providers

Cardiovascular Disease Physician share within California

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

Medicare quality performance — MIPS

CATHLEEN BAIREY MERZ, M.D.'s 2023 MIPS final score plotted against the Cardiovascular Disease Physician national average

High performer (top quartile)
MIPS Final Score
87.6775/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Cardiovascular Disease Physician) — 87.6775/100 vs national avg 83.1

0%100%National avg83%87.7%
MIPS final score (Cardiovascular Disease Physician) — 87.6775/100 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).

CATHLEEN BAIREY MERZ, M.D. is a Cardiovascular Disease Physician provider practicing in LOS ANGELES, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1447238324. 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.

CATHLEEN BAIREY MERZ, M.D. appears in the CMS NPPES registry as a Cardiovascular Disease Physician provider holding M.D. credentials at 444 S SAN VICENTE BLVD, LOS ANGELES, CA, 90048, with a listed phone of (310) 423-9680. NPI 1447238324 was issued on 01/03/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what BAIREY MERZ 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 555 prescription claims written by this provider, covering 149 Medicare beneficiaries and totaling roughly $66K in drug spend, split 10% brand-name and 90% 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 87.6775/100 for the 2023 performance year (Quality 80.8666, Cost 49.4287), 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

444 S SAN VICENTE BLVD
LOS ANGELES, CA 90048

Provider Details

NPI 1447238324
Specialty Cardiovascular Disease Physician
Credentials M.D.
Gender Female
NPI Issued 01/03/2006

CMS Quality Score (MIPS)

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

87.6775
Final Score
Avg: 83.1
80.8666
Quality
49.4287
Cost
99
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where CATHLEEN BAIREY MERZ, 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.

CEDARS-SINAI MEDICAL CENTER
★★★★★ 5/5
WEST HOLLYWOOD, CA
Acute Care Hospitals
CMS CCN: 050625

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 CATHLEEN BAIREY MERZ, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$223.9K

Largest payer

iRhythm Technologies, Inc.

Most common payment type

Travel and Lodging

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.

License & disciplinary context — California MBC 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 ~150K California medical licensees in 2023 — they are NOT specific to CATHLEEN BAIREY MERZ, M.D.. To verify CATHLEEN BAIREY MERZ, M.D.'s current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC 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 California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

CATHLEEN BAIREY MERZ, M.D. — brand share 10.0%
Specialty average (est.)

10% brand-name claims vs 90% generic, on 555 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.

555
Total Claims
$66K
Total Drug Cost
149
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,463
Total Day Supply
43,746
Brand vs Generic
10% brand / 90% generic
Brand Drug Cost
$53K
Generic Drug Cost
$13K

Patient Demographics

Average Patient Age
73.6 years
Avg HCC Risk Score
1.30
Age Distribution
<65: 14, 65-74: 64, 75-84: 58, 85+: 13

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Rosuvastatin Calcium
67
Amlodipine Besylate
56
Carvedilol
39
Atorvastatin Calcium
30
Losartan Potassium
28
Ezetimibe
26
Diltiazem 24hr Er (Cd)
Diltiazem Hcl
24
Telmisartan
20
Ramipril
18
Nitroglycerin Patch
Nitroglycerin
17

* 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 CATHLEEN BAIREY MERZ, 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

CATHLEEN BAIREY MERZ, M.D.'s 555 claims are below the specialty average of 3,033.

Nearby Cardiovascular Disease Physician Providers in California

Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as BAIREY MERZ.

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

Frequently Asked Questions

What is CATHLEEN BAIREY MERZ, M.D.'s specialty?
CATHLEEN BAIREY MERZ, M.D. specializes in Cardiovascular Disease Physician and practices in LOS ANGELES, California. Credentials: M.D..
How much does CATHLEEN BAIREY MERZ, M.D. prescribe under Medicare Part D?
In 2023, CATHLEEN BAIREY MERZ, M.D. wrote 555 Medicare Part D claims totaling $66K in drug costs for 149 beneficiaries.
What is CATHLEEN BAIREY MERZ, M.D.'s Medicare quality score?
CATHLEEN BAIREY MERZ, M.D. has a CMS MIPS Final Score of 87.6775/100 (Quality: 80.8666, Cost: 49.4287). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is CATHLEEN BAIREY MERZ, M.D. located?
CATHLEEN BAIREY MERZ, M.D. is located at 444 S SAN VICENTE BLVD, LOS ANGELES, CA, 90048. Phone: (310) 423-9680.
What is CATHLEEN BAIREY MERZ, M.D.'s NPI number?
CATHLEEN BAIREY MERZ, M.D.'s National Provider Identifier (NPI) is 1447238324, issued on 01/03/2006.
Does CATHLEEN BAIREY MERZ, M.D. prescribe more brand-name or generic drugs?
CATHLEEN BAIREY MERZ, M.D.'s prescribing is 10% brand-name and 90% generic drugs by claim count, with $53K 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 CATHLEEN BAIREY MERZ, M.D. prescribe most often?
Based on 2023 Medicare Part D data, CATHLEEN BAIREY MERZ, M.D.'s most frequently prescribed drugs include Rosuvastatin Calcium, Amlodipine Besylate, Carvedilol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CATHLEEN BAIREY MERZ, M.D. accept Medicare?
CATHLEEN BAIREY MERZ, M.D. appears in CMS Medicare data with 555 Part D claims and 149 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CATHLEEN BAIREY MERZ, M.D.'s credentials?
CATHLEEN BAIREY MERZ, M.D.'s NPI is 1447238324 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