2026 NPPES data Cardiovascular Disease Physician NPI 1073599858 M.D.
Verify on CMS →

THOMAS AHERN, M.D.

Cardiovascular Disease Physician in LA JOLLA, 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
407
Medicare Part D claims · 165 beneficiaries · Cardiovascular Disease Physician avg: 3K
Generic prescribing
81%
generic claims · 19% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: THOMAS AHERN, M.D. is a Cardiovascular Disease Physician ([object Object]) practicing in LA JOLLA, California with a Medicare Part D prescribing footprint of 407 claims across 165 beneficiaries — 19% brand-name prescribing .

What stands out: THOMAS AHERN, M.D. filed 407 Medicare Part D claims in 2023 across LA JOLLA, California. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

THOMAS AHERN, 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).

THOMAS AHERN, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 12/22/2005

NPI 1073599858

Primary specialty

Cardiovascular Disease Physician

Mid-sized

24,795 US NPIs in this specialty

Medicare Part D claims

407 87% vs specialty avg

2023 prescription claims

Specialty avg: 3,033

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

Specialty board-certification context

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

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

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

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

THOMAS AHERN, M.D. is a Cardiovascular Disease Physician provider practicing in LA JOLLA, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1073599858. 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.

THOMAS AHERN, M.D. appears in the CMS NPPES registry as a Cardiovascular Disease Physician provider holding M.D. credentials at 10666 N TORREY PINES RD, LA JOLLA, CA, 92037, with a listed phone of (858) 554-4039. NPI 1073599858 was issued on 12/22/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what AHERN 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 407 prescription claims written by this provider, covering 165 Medicare beneficiaries and totaling roughly $130K in drug spend, split 19% brand-name and 81% 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.

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

10666 N TORREY PINES RD
LA JOLLA, CA 92037

Provider Details

NPI 1073599858
Specialty Cardiovascular Disease Physician
Credentials M.D.
Gender Male
NPI Issued 12/22/2005

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 THOMAS AHERN, M.D.. To verify THOMAS AHERN, 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

THOMAS AHERN, M.D. — brand share 19.0%
Specialty average (est.)

19% brand-name claims vs 81% generic, on 407 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.

407
Total Claims
$130K
Total Drug Cost
165
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,052
Total Day Supply
31,504
Brand vs Generic
19% brand / 81% generic
Brand Drug Cost
$92K
Generic Drug Cost
$38K

Patient Demographics

Average Patient Age
79.4 years
Avg HCC Risk Score
1.60
Gender Split
48% female / 52% 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
Eliquis
Apixaban
38
Losartan Potassium
34
Atorvastatin Calcium
29
Metoprolol Succinate
28
Lisinopril
20
Ezetimibe
16
Spironolactone
15
Isosorbide Mononitrate Er
Isosorbide Mononitrate
12

* 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 THOMAS AHERN, 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

THOMAS AHERN, M.D.'s 407 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 AHERN.

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

Frequently Asked Questions

What is THOMAS AHERN, M.D.'s specialty?
THOMAS AHERN, M.D. specializes in Cardiovascular Disease Physician and practices in LA JOLLA, California. Credentials: M.D..
How much does THOMAS AHERN, M.D. prescribe under Medicare Part D?
In 2023, THOMAS AHERN, M.D. wrote 407 Medicare Part D claims totaling $130K in drug costs for 165 beneficiaries.
Where is THOMAS AHERN, M.D. located?
THOMAS AHERN, M.D. is located at 10666 N TORREY PINES RD, LA JOLLA, CA, 92037. Phone: (858) 554-4039.
What is THOMAS AHERN, M.D.'s NPI number?
THOMAS AHERN, M.D.'s National Provider Identifier (NPI) is 1073599858, issued on 12/22/2005.
Does THOMAS AHERN, M.D. prescribe more brand-name or generic drugs?
THOMAS AHERN, M.D.'s prescribing is 19% brand-name and 81% generic drugs by claim count, with $92K 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 THOMAS AHERN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, THOMAS AHERN, M.D.'s most frequently prescribed drugs include Eliquis, Losartan Potassium, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does THOMAS AHERN, M.D. accept Medicare?
THOMAS AHERN, M.D. appears in CMS Medicare data with 407 Part D claims and 165 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify THOMAS AHERN, M.D.'s credentials?
THOMAS AHERN, M.D.'s NPI is 1073599858 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