2026 NPPES data Family Medicine Physician NPI 1265497093 MD
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JAMES AMBERG, MD

Family Medicine Physician in LA MESA, 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
143
Medicare Part D claims · Family Medicine Physician avg: 3K
Generic prescribing
59%
generic claims · 41% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

JAMES AMBERG, MD filed 143 Medicare Part D claims in 2023 as a Family Medicine Physician in LA MESA, California, prescribing 59% generic.

143
Part D claims, 2023
59%
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.

JAMES AMBERG, MD's Medicare Part D volume vs every U.S. prescriber

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

143 35th percentile higher than 35% of 1,370,886 prescribers

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

JAMES AMBERG, MD 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 JAMES AMBERG, MD?

Quality data not reported

NPI registry status

Active

Issued 04/17/2006

NPI 1265497093

Primary specialty

Family Medicine Physician

High-volume

147,640 US NPIs in this specialty

Medicare Part D claims

143 96% vs specialty avg

2023 prescription claims

Specialty avg: 3,418

Specialty distribution in California

How Family Medicine Physician compares to other specialties among California providers

California providers

Family Medicine Physician share within California

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

Specialty board-certification context

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

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

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

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

JAMES AMBERG, MD appears in the CMS NPPES registry as a Family Medicine Physician provider holding MD credentials at 5525 GROSSMONT CENTER DR, LA MESA, CA, 91942, with a listed phone of (619) 644-6500. NPI 1265497093 was issued on 04/17/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what AMBERG 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 143 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $19K in drug spend, split 41% brand-name and 59% 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.

Family Medicine Physician is a high-volume specialty nationwide, with 147,640 enrolled providers across 56 states and an average of 3,418 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

5525 GROSSMONT CENTER DR
LA MESA, CA 91942

Provider Details

NPI 1265497093
Specialty Family Medicine Physician
Credentials MD
Gender Male
NPI Issued 04/17/2006

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 JAMES AMBERG, MD. To verify JAMES AMBERG, MD'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 · Above average

JAMES AMBERG, MD — brand share 41.0%
Specialty average (est.)

41% brand-name claims vs 59% generic, on 143 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.

143
Total Claims
$19K
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
143
Total Day Supply
4,050
Brand vs Generic
41% brand / 59% generic
Brand Drug Cost
$11K
Generic Drug Cost
$8K

Patient Demographics

Average Patient Age
49.6 years
Avg HCC Risk Score
0.39

Top Prescribed Drugs (Medicare Part D)

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

What JAMES AMBERG, MD prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Levothyroxine Sodium
39
Atomoxetine Hcl
13
Creon
Lipase/Protease/Amylase
13
Dexlansoprazole Dr
Dexlansoprazole
13
Estradiol
13
Lubiprostone
13
Medroxyprogesterone Acetate
13
Propranolol Hcl
13
Tamsulosin Hcl
13

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

Family Medicine Physician Overview

How JAMES AMBERG, MD fits within the Family Medicine Physician landscape nationally.

147,640
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider

JAMES AMBERG, MD's 143 claims are below the specialty average of 3,418.

Nearby Family Medicine Physician Providers in California

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

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

Frequently Asked Questions

What is JAMES AMBERG, MD's specialty?
JAMES AMBERG, MD specializes in Family Medicine Physician and practices in LA MESA, California. Credentials: MD.
How much does JAMES AMBERG, MD prescribe under Medicare Part D?
In 2023, JAMES AMBERG, MD wrote 143 Medicare Part D claims totaling $19K in drug costs for N/A beneficiaries.
Where is JAMES AMBERG, MD located?
JAMES AMBERG, MD is located at 5525 GROSSMONT CENTER DR, LA MESA, CA, 91942. Phone: (619) 644-6500.
What is JAMES AMBERG, MD's NPI number?
JAMES AMBERG, MD's National Provider Identifier (NPI) is 1265497093, issued on 04/17/2006.
Does JAMES AMBERG, MD prescribe more brand-name or generic drugs?
JAMES AMBERG, MD's prescribing is 41% brand-name and 59% generic drugs by claim count, with $11K in brand drug costs.
How many Family Medicine Physician providers are there in the US?
There are 147,640 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does JAMES AMBERG, MD prescribe most often?
Based on 2023 Medicare Part D data, JAMES AMBERG, MD's most frequently prescribed drugs include Levothyroxine Sodium, Atomoxetine Hcl, Creon. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JAMES AMBERG, MD accept Medicare?
JAMES AMBERG, MD appears in CMS Medicare data with 143 Part D claims and N/A Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JAMES AMBERG, MD's credentials?
JAMES AMBERG, MD's NPI is 1265497093 with credentials MD. 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