2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1043742588 MD, MPH
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JOHANNA GERWER, MD, MPH

Endocrinology, Diabetes & Metabolism Physician in SAN DIEGO, 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
428
Medicare Part D claims · 89 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
46%
generic claims · 54% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$396.95
13 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

JOHANNA GERWER, MD, MPH filed 428 Medicare Part D claims in 2023 as a Endocrinology, Diabetes & Metabolism Physician in SAN DIEGO, California, prescribing 46% generic.

428
Part D claims, 2023
46%
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.

JOHANNA GERWER, MD, MPH's Medicare Part D volume vs every U.S. prescriber

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

428 Top 38% higher than 62% 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%). This entry sits in this band. 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 certification likely (heuristic — not verified)

JOHANNA GERWER, MD, MPH practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 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 JOHANNA GERWER, MD, MPH?

Quality data not reported

NPI registry status

Active

Issued 04/03/2017

NPI 1043742588

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

428 84% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

Specialty distribution in California

How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among California providers

California providers

Endocrinology, Diabetes & Metabolism Physician share within California

1. Endocrinology, Diabetes & Metabolism Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Endocrinology, Diabetes & Metabolism Physician share within California

Specialty board-certification context

Estimated specialty board-certified rate — Endocrinology, Diabetes & Metabolism Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Endocrinology, Diabetes & Metabolism Physician ABMS/AOA estimate

Est. board-certified rate (Endocrinology, Diabetes & Metabolism Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Endocrinology, Diabetes & Metabolism 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).

JOHANNA GERWER, MD, MPH appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider holding MD, MPH credentials at 1809 NATIONAL AVE, SAN DIEGO, CA, 92113, with a listed phone of (619) 515-2300. NPI 1043742588 was issued on 04/03/2017. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GERWER 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 428 prescription claims written by this provider, covering 89 Medicare beneficiaries and totaling roughly $228K in drug spend, split 54% brand-name and 46% 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.

Endocrinology, Diabetes & Metabolism Physician is a mid-sized specialty nationwide, with 7,852 enrolled providers across 54 states and an average of 2,639 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

1809 NATIONAL AVE
SAN DIEGO, CA 92113

Provider Details

NPI 1043742588
Specialty Endocrinology, Diabetes & Metabolism Physician
Credentials MD, MPH
Gender Female
NPI Issued 04/03/2017

Hospital and facility affiliations

Facilities where JOHANNA GERWER, MD, MPH 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.

FAMILY HEALTH CENTERS OF SAN DIEGO INC
SAN DIEGO, CA

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 JOHANNA GERWER, MD, MPH. Source: openpaymentsdata.cms.gov.

Total received

$397

Largest payer

Tandem Diabetes Care, Inc.

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 JOHANNA GERWER, MD, MPH. To verify JOHANNA GERWER, MD, MPH'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 · Brand-heavy

JOHANNA GERWER, MD, MPH — brand share 54.0%
Specialty average (est.)

54% brand-name claims vs 46% generic, on 428 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.

428
Total Claims
$228K
Total Drug Cost
89
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
771
Total Day Supply
22,276
Brand vs Generic
54% brand / 46% generic
Brand Drug Cost
$222K
Generic Drug Cost
$2K

Patient Demographics

Average Patient Age
66.1 years
Avg HCC Risk Score
2.17
Gender Split
58% female / 42% male
Age Distribution
<65: 24, 65-74: 50, 75-84: N/A, 85+: N/A

Top Prescribed Drugs (Medicare Part D)

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

What JOHANNA GERWER, MD, MPH 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
Trulicity
Dulaglutide
51
Levothyroxine Sodium
30
Metformin Hcl
30
Jardiance
Empagliflozin
19
Novolog Flexpen
Insulin Aspart
18
Ozempic
Semaglutide
16
Levemir
Insulin Detemir
15
Glipizide
11
Metformin Hcl Er
Metformin Hcl
11
Basaglar Kwikpen U-100
"Insulin Glargine
N/A

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

Endocrinology, Diabetes & Metabolism Physician Overview

How JOHANNA GERWER, MD, MPH fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.

7,852
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,639
Avg Claims per Provider

JOHANNA GERWER, MD, MPH's 428 claims are below the specialty average of 2,639.

Nearby Endocrinology, Diabetes & Metabolism Physician Providers in California

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

Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is JOHANNA GERWER, MD, MPH's specialty?
JOHANNA GERWER, MD, MPH specializes in Endocrinology, Diabetes & Metabolism Physician and practices in SAN DIEGO, California. Credentials: MD, MPH.
How much does JOHANNA GERWER, MD, MPH prescribe under Medicare Part D?
In 2023, JOHANNA GERWER, MD, MPH wrote 428 Medicare Part D claims totaling $228K in drug costs for 89 beneficiaries.
Where is JOHANNA GERWER, MD, MPH located?
JOHANNA GERWER, MD, MPH is located at 1809 NATIONAL AVE, SAN DIEGO, CA, 92113. Phone: (619) 515-2300.
What is JOHANNA GERWER, MD, MPH's NPI number?
JOHANNA GERWER, MD, MPH's National Provider Identifier (NPI) is 1043742588, issued on 04/03/2017.
Does JOHANNA GERWER, MD, MPH prescribe more brand-name or generic drugs?
JOHANNA GERWER, MD, MPH's prescribing is 54% brand-name and 46% generic drugs by claim count, with $222K in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US?
There are 7,852 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,639 Medicare Part D claims per year.
What drugs does JOHANNA GERWER, MD, MPH prescribe most often?
Based on 2023 Medicare Part D data, JOHANNA GERWER, MD, MPH's most frequently prescribed drugs include Trulicity, Levothyroxine Sodium, Metformin Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JOHANNA GERWER, MD, MPH accept Medicare?
JOHANNA GERWER, MD, MPH appears in CMS Medicare data with 428 Part D claims and 89 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JOHANNA GERWER, MD, MPH's credentials?
JOHANNA GERWER, MD, MPH's NPI is 1043742588 with credentials MD, MPH. 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