2026 NPPES data Internal Medicine Physician NPI 1518405661 MD
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JOEL ACAB, MD

Internal Medicine Physician in WALNUT CREEK, 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
5K
Medicare Part D claims · 795 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
91%
generic claims · 9% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: JOEL ACAB, MD is a Internal Medicine Physician ([object Object]) practicing in WALNUT CREEK, California with a Medicare Part D prescribing footprint of 5K claims across 795 beneficiaries — 9% brand-name prescribing .

What stands out: JOEL ACAB, MD filed 5,462 Medicare Part D claims in 2023 across WALNUT CREEK, California. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

JOEL ACAB, MD 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).

JOEL ACAB, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 02/09/2017

NPI 1518405661

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

5,462 101% 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).

JOEL ACAB, MD is a Internal Medicine Physician provider practicing in WALNUT CREEK, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1518405661. 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.

JOEL ACAB, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 320 LENNON LN, WALNUT CREEK, CA, 94598, with a listed phone of (925) 906-2040. NPI 1518405661 was issued on 02/09/2017. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ACAB 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 5,462 prescription claims written by this provider, covering 795 Medicare beneficiaries and totaling roughly $265K in drug spend, split 9% brand-name and 91% generic by claim count, with an opioid prescribing rate of 2.2%. 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

320 LENNON LN
WALNUT CREEK, CA 94598

Provider Details

NPI 1518405661
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 02/09/2017

Hospital and facility affiliations

Facilities where JOEL ACAB, MD 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.

PERMANENTE MEDICAL GROUP INC
WALNUT CREEK, 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).

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 JOEL ACAB, MD. To verify JOEL ACAB, 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 · Generic-heavy

JOEL ACAB, MD — brand share 9.0%
Specialty average (est.)

9% brand-name claims vs 91% generic, on 5,462 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.

5,462
Total Claims
$265K
Total Drug Cost
795
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
13,292
Total Day Supply
385,865
Brand vs Generic
9% brand / 91% generic
Brand Drug Cost
$161K
Generic Drug Cost
$103K
Opioid Claims
119 (2.2% rate)
Antibiotic Claims
165

Patient Demographics

Average Patient Age
75.2 years
Avg HCC Risk Score
1.21
Gender Split
57% female / 43% male
Age Distribution
<65: 31, 65-74: 349, 75-84: 305, 85+: 110

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
427
Losartan Potassium
247
Amlodipine Besylate
239
Levothyroxine Sodium
201
Lisinopril
182
Fluticasone Propionate
161
Gabapentin
147
Albuterol Sulfate Hfa
Albuterol Sulfate
128
Tamsulosin Hcl
124
Hydrochlorothiazide
119

* 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 JOEL ACAB, MD 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

JOEL ACAB, MD's 5,462 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 ACAB.

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

Frequently Asked Questions

What is JOEL ACAB, MD's specialty?
JOEL ACAB, MD specializes in Internal Medicine Physician and practices in WALNUT CREEK, California. Credentials: MD.
How much does JOEL ACAB, MD prescribe under Medicare Part D?
In 2023, JOEL ACAB, MD wrote 5,462 Medicare Part D claims totaling $265K in drug costs for 795 beneficiaries.
Where is JOEL ACAB, MD located?
JOEL ACAB, MD is located at 320 LENNON LN, WALNUT CREEK, CA, 94598. Phone: (925) 906-2040.
What is JOEL ACAB, MD's NPI number?
JOEL ACAB, MD's National Provider Identifier (NPI) is 1518405661, issued on 02/09/2017.
Does JOEL ACAB, MD prescribe more brand-name or generic drugs?
JOEL ACAB, MD's prescribing is 9% brand-name and 91% generic drugs by claim count, with $161K in brand drug costs.
Does JOEL ACAB, MD prescribe opioids?
Yes, JOEL ACAB, MD had 119 opioid claims in 2023 with an opioid prescribing rate of 2.2%.
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 JOEL ACAB, MD prescribe most often?
Based on 2023 Medicare Part D data, JOEL ACAB, MD's most frequently prescribed drugs include Atorvastatin Calcium, Losartan Potassium, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JOEL ACAB, MD accept Medicare?
JOEL ACAB, MD appears in CMS Medicare data with 5,462 Part D claims and 795 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JOEL ACAB, MD's credentials?
JOEL ACAB, MD's NPI is 1518405661 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