2026 NPPES data Internal Medicine Physician NPI 1669621058 M.D.
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ALBERTO ALONSO, M.D.

Internal Medicine Physician in HUNTINGTON PARK, 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
21K
Medicare Part D claims · 580 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
83%
generic claims · 17% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.1K
52 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: ALBERTO ALONSO, M.D. is a Internal Medicine Physician ([object Object]) practicing in HUNTINGTON PARK, California with a Medicare Part D prescribing footprint of 21K claims across 580 beneficiaries — 17% brand-name prescribing . Industry payments of $1.1K across 52 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: ALBERTO ALONSO, M.D. filed 20,721 Medicare Part D claims in 2023 across HUNTINGTON PARK, California. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

ALBERTO ALONSO, 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).

ALBERTO ALONSO, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 09/10/2008

NPI 1669621058

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

20,721 663% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in California

How Internal Medicine Physician compares to other specialties among California providers

California providers

Internal Medicine Physician share within California

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

Specialty board-certification context

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

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

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

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

ALBERTO ALONSO, M.D. is a Internal Medicine Physician provider practicing in HUNTINGTON PARK, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1669621058. 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.

ALBERTO ALONSO, M.D. appears in the CMS NPPES registry as a Internal Medicine Physician provider holding M.D. credentials at 6611 SEVILLE AVE, HUNTINGTON PARK, CA, 90255, with a listed phone of (562) 881-3043. NPI 1669621058 was issued on 09/10/2008. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ALONSO 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 20,721 prescription claims written by this provider, covering 580 Medicare beneficiaries and totaling roughly $2.4 million in drug spend, split 17% brand-name and 83% generic by claim count, with an opioid prescribing rate of 1.5%. 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.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

6611 SEVILLE AVE
HUNTINGTON PARK, CA 90255

Provider Details

NPI 1669621058
Specialty Internal Medicine Physician
Credentials M.D.
Gender Male
NPI Issued 09/10/2008

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 ALBERTO ALONSO, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$1.1K

Largest payer

AstraZeneca Pharmaceuticals LP

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.

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 ALBERTO ALONSO, M.D.. To verify ALBERTO ALONSO, 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

ALBERTO ALONSO, M.D. — brand share 17.0%
Specialty average (est.)

17% brand-name claims vs 83% generic, on 20,721 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.

20,721
Total Claims
$2.4M
Total Drug Cost
580
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
36,031
Total Day Supply
1,026,457
Brand vs Generic
17% brand / 83% generic
Brand Drug Cost
$1.6M
Generic Drug Cost
$774K
Opioid Claims
307 (1.5% rate)
Antibiotic Claims
520

Patient Demographics

Average Patient Age
76.1 years
Avg HCC Risk Score
2.19
Gender Split
57% female / 43% male
Age Distribution
<65: 36, 65-74: 215, 75-84: 235, 85+: 94

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
1,015
Gabapentin
823
Metformin Hcl
576
Levothyroxine Sodium
525
Losartan Potassium
455
Amlodipine Besylate
399
Lisinopril
366
Omeprazole
353
Furosemide
352
Pantoprazole Sodium
343

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

Internal Medicine Physician Overview

How ALBERTO ALONSO, M.D. fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

ALBERTO ALONSO, M.D.'s 20,721 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in California

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

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is ALBERTO ALONSO, M.D.'s specialty?
ALBERTO ALONSO, M.D. specializes in Internal Medicine Physician and practices in HUNTINGTON PARK, California. Credentials: M.D..
How much does ALBERTO ALONSO, M.D. prescribe under Medicare Part D?
In 2023, ALBERTO ALONSO, M.D. wrote 20,721 Medicare Part D claims totaling $2.4M in drug costs for 580 beneficiaries.
Where is ALBERTO ALONSO, M.D. located?
ALBERTO ALONSO, M.D. is located at 6611 SEVILLE AVE, HUNTINGTON PARK, CA, 90255. Phone: (562) 881-3043.
What is ALBERTO ALONSO, M.D.'s NPI number?
ALBERTO ALONSO, M.D.'s National Provider Identifier (NPI) is 1669621058, issued on 09/10/2008.
Does ALBERTO ALONSO, M.D. prescribe more brand-name or generic drugs?
ALBERTO ALONSO, M.D.'s prescribing is 17% brand-name and 83% generic drugs by claim count, with $1.6M in brand drug costs.
Does ALBERTO ALONSO, M.D. prescribe opioids?
Yes, ALBERTO ALONSO, M.D. had 307 opioid claims in 2023 with an opioid prescribing rate of 1.5%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does ALBERTO ALONSO, M.D. prescribe most often?
Based on 2023 Medicare Part D data, ALBERTO ALONSO, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Gabapentin, Metformin Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does ALBERTO ALONSO, M.D. accept Medicare?
ALBERTO ALONSO, M.D. appears in CMS Medicare data with 20,721 Part D claims and 580 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify ALBERTO ALONSO, M.D.'s credentials?
ALBERTO ALONSO, M.D.'s NPI is 1669621058 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