2026 NPPES data Nephrology Physician NPI 1437366804 M.D.
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RICHARD HOROWITZ, M.D.

Nephrology 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
2K
Medicare Part D claims · 155 beneficiaries · Nephrology Physician avg: 1K
Generic prescribing
90%
generic claims · 10% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

RICHARD HOROWITZ, M.D. filed 1,579 Medicare Part D claims in 2023 as a Nephrology Physician in LOS ANGELES, California, prescribing 90% generic.

2K
Part D claims, 2023
90%
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.

RICHARD HOROWITZ, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

1,579 Top 19% higher than 81% of 1,370,886 prescribers

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

RICHARD HOROWITZ, 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 RICHARD HOROWITZ, M.D.?

Quality data not reported

NPI registry status

Active

Issued 05/16/2007

NPI 1437366804

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

1,579 9% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

Specialty distribution in California

How Nephrology Physician compares to other specialties among California providers

California providers

Nephrology Physician share within California

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

Specialty board-certification context

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

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

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

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

RICHARD HOROWITZ, M.D. is a Nephrology Physician provider practicing in LOS ANGELES, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1437366804. 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.

RICHARD HOROWITZ, M.D. appears in the CMS NPPES registry as a Nephrology Physician provider holding M.D. credentials at 8635 W 3RD ST, LOS ANGELES, CA, 90048, with a listed phone of (310) 358-7200. NPI 1437366804 was issued on 05/16/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what HOROWITZ 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 1,579 prescription claims written by this provider, covering 155 Medicare beneficiaries and totaling roughly $160K in drug spend, split 10% brand-name and 90% generic by claim count, with an opioid prescribing rate of 2.3%. 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.

Nephrology Physician is a mid-sized specialty nationwide, with 10,534 enrolled providers across 55 states and an average of 1,454 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

8635 W 3RD ST
LOS ANGELES, CA 90048

Provider Details

NPI 1437366804
Specialty Nephrology Physician
Credentials M.D.
Gender Male
NPI Issued 05/16/2007

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 RICHARD HOROWITZ, M.D.. To verify RICHARD HOROWITZ, 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

RICHARD HOROWITZ, M.D. — brand share 10.0%
Specialty average (est.)

10% brand-name claims vs 90% generic, on 1,579 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.

1,579
Total Claims
$160K
Total Drug Cost
155
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
3,097
Total Day Supply
89,427
Brand vs Generic
10% brand / 90% generic
Brand Drug Cost
$111K
Generic Drug Cost
$47K
Opioid Claims
37 (2.3% rate)
Antibiotic Claims
75

Patient Demographics

Average Patient Age
73.1 years
Avg HCC Risk Score
1.16
Gender Split
55% female / 45% 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
Levothyroxine Sodium
75
Zolpidem Tartrate
62
Atorvastatin Calcium
58
Rosuvastatin Calcium
49
Losartan Potassium
48
Alprazolam
41
Pantoprazole Sodium
40
Amlodipine Besylate
36
Chlorthalidone
36
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
31

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

Nephrology Physician Overview

How RICHARD HOROWITZ, M.D. fits within the Nephrology Physician landscape nationally.

10,534
Nephrology Physician Providers in US
55
States with Nephrology Physician
1,454
Avg Claims per Provider

RICHARD HOROWITZ, M.D.'s 1,579 claims are above the specialty average of 1,454.

Nearby Nephrology Physician Providers in California

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

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

Frequently Asked Questions

What is RICHARD HOROWITZ, M.D.'s specialty?
RICHARD HOROWITZ, M.D. specializes in Nephrology Physician and practices in LOS ANGELES, California. Credentials: M.D..
How much does RICHARD HOROWITZ, M.D. prescribe under Medicare Part D?
In 2023, RICHARD HOROWITZ, M.D. wrote 1,579 Medicare Part D claims totaling $160K in drug costs for 155 beneficiaries.
Where is RICHARD HOROWITZ, M.D. located?
RICHARD HOROWITZ, M.D. is located at 8635 W 3RD ST, LOS ANGELES, CA, 90048. Phone: (310) 358-7200.
What is RICHARD HOROWITZ, M.D.'s NPI number?
RICHARD HOROWITZ, M.D.'s National Provider Identifier (NPI) is 1437366804, issued on 05/16/2007.
Does RICHARD HOROWITZ, M.D. prescribe more brand-name or generic drugs?
RICHARD HOROWITZ, M.D.'s prescribing is 10% brand-name and 90% generic drugs by claim count, with $111K in brand drug costs.
Does RICHARD HOROWITZ, M.D. prescribe opioids?
Yes, RICHARD HOROWITZ, M.D. had 37 opioid claims in 2023 with an opioid prescribing rate of 2.3%.
How many Nephrology Physician providers are there in the US?
There are 10,534 Nephrology Physician providers across 55 states in the US. The average Nephrology Physician provider writes 1,454 Medicare Part D claims per year.
What drugs does RICHARD HOROWITZ, M.D. prescribe most often?
Based on 2023 Medicare Part D data, RICHARD HOROWITZ, M.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Zolpidem Tartrate, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does RICHARD HOROWITZ, M.D. accept Medicare?
RICHARD HOROWITZ, M.D. appears in CMS Medicare data with 1,579 Part D claims and 155 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify RICHARD HOROWITZ, M.D.'s credentials?
RICHARD HOROWITZ, M.D.'s NPI is 1437366804 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