NPI registry status
Active
2026 NPPES data Hospitalist Physician NPI 1134418171 M.D.
Verify on CMS → Brian Apter, M.D.
Hospitalist Physician in Pasadena, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 16,825 in Hospitalist Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
569
Medicare Part D claims · 172 beneficiaries · Hospitalist Physician avg: 888
Generic prescribing
87%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Brian Apter, M.D. filed 569 Medicare Part D claims in 2023 as a Hospitalist Physician in Pasadena, California, prescribing 87% generic.
- 569
- Part D claims, 2023
- 87%
- 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.
Brian Apter, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
569 Top 34% higher than 66% of 1,370,886 prescribers
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)
Brian Apter, M.D. 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 Brian Apter, M.D.?
Quality data not reportedPrimary specialty
Hospitalist Physician
Medicare Part D claims
569 36% vs specialty avg
Specialty distribution in California
How Hospitalist Physician compares to other specialties among California providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Hospitalist Physician. Verify directly:
How MIPS and board certification work
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).
Brian Apter, M.D. appears in the CMS NPPES registry as a Hospitalist Physician provider holding M.D. credentials at 393 E WALNUT ST, Pasadena, CA, 91188, with a listed phone of (415) 310-1938. NPI 1134418171 was issued on 03/30/2011.
Medicare Part D records for calendar year 2023 show 569 prescription claims written by this provider, covering 172 Medicare beneficiaries and totaling roughly $34K in drug spend, split 13% brand-name and 87% generic by claim count.
Hospitalist Physician is a mid-sized specialty nationwide, with 16,825 enrolled providers across 54 states and an average of 888 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
Provider Details
| NPI | 1134418171 |
|---|---|
| Specialty | Hospitalist Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 03/30/2011 |
Hospital and facility affiliations
Facilities where Brian Apter, M.D. 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.
Southern California Permanente Medical Group
Riverside, 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 Brian Apter, M.D.. To verify Brian Apter, 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
Brian Apter, M.D. - brand share 13.0%
Hospitalist Physician average
13% brand-name claims vs 87% generic, on 569 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.
569
Total Claims
$34K
Total Drug Cost
172
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,174
- Total Day Supply
- 32,217
- Brand vs Generic
- 13% brand / 87% generic
- Brand Drug Cost
- $22K
- Generic Drug Cost
- $12K
- Antibiotic Claims
- 66
Patient Demographics
- Average Patient Age
- 75.4 years
- Avg HCC Risk Score
- 2.73
- Gender Split
- 47% female / 53% male
- Age Distribution
- <65: 21, 65-74: 54, 75-84: 61, 85+: 36
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Brian Apter, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Furosemide
Furosemide
38 claims
- Potassium Chloride
Potassium Chloride
37 claims
- Amlodipine Besylate
Amlodipine Besylate
35 claims
- Hydralazine Hcl
Hydralazine Hcl
29 claims
- Atorvastatin Calcium
Atorvastatin Calcium
22 claims
- Isosorbide Mononit…
Isosorbide Mononitrate Er
20 claims
- Metoprolol Tartrate
Metoprolol Tartrate
20 claims
- Cefpodoxime Proxetil
Cefpodoxime Proxetil
19 claims
| Drug | Claims |
|---|---|
| Furosemide | 38 |
| Potassium Chloride | 37 |
| Amlodipine Besylate | 35 |
| Hydralazine Hcl | 29 |
| Atorvastatin Calcium | 22 |
| Isosorbide Mononitrate Er Isosorbide Mononitrate | 20 |
| Metoprolol Tartrate | 20 |
| Cefpodoxime Proxetil | 19 |
| Pantoprazole Sodium | 18 |
| Losartan Potassium | 17 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Hospitalist Physician Overview
How Brian Apter, M.D. fits within the Hospitalist Physician landscape nationally.
16,825
Hospitalist Physician Providers in US
54
States with Hospitalist Physician
888
Avg Claims per Provider
Brian Apter, M.D.'s 569 claims are below the specialty average of 888.
Nearby Hospitalist Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Apter.
Dr. Zina Abbas
M.D.
Chula Vista, CA
Dr. Mehrdad Abbasi
MD
Rancho Mirage, CA
Dr. Abdul Abdali
M.D.
French Camp, CA
Dr. Anwar Abdelhadi
M.D.
Orange, CA
Dr. Farid Abdelmalak
M.D.
Santa Monica, CA
Compare Hospitalist Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the California medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Hospitalist Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Brian Apter, M.D.'s specialty? ▼
Brian Apter, M.D. specializes in Hospitalist Physician and practices in Pasadena, California. Credentials: M.D..
How much does Brian Apter, M.D. prescribe under Medicare Part D? ▼
In 2023, Brian Apter, M.D. wrote 569 Medicare Part D claims totaling $34K in drug costs for 172 beneficiaries.
Where is Brian Apter, M.D. located? ▼
Brian Apter, M.D. is located at 393 E WALNUT ST, Pasadena, CA, 91188. Phone: (415) 310-1938.
What is Brian Apter, M.D.'s NPI number? ▼
Brian Apter, M.D.'s National Provider Identifier (NPI) is 1134418171, issued on 03/30/2011.
Does Brian Apter, M.D. prescribe more brand-name or generic drugs? ▼
Brian Apter, M.D.'s prescribing is 13% brand-name and 87% generic drugs by claim count, with $22K in brand drug costs.
How many Hospitalist Physician providers are there in the US? ▼
There are 16,825 Hospitalist Physician providers across 54 states in the US. The average Hospitalist Physician provider writes 888 Medicare Part D claims per year.
What drugs does Brian Apter, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Brian Apter, M.D.'s most frequently prescribed drugs include Furosemide, Potassium Chloride, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Brian Apter, M.D. accept Medicare? ▼
Brian Apter, M.D. appears in CMS Medicare data with 569 Part D claims and 172 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Brian Apter, M.D.'s credentials? ▼
Brian Apter, M.D.'s NPI is 1134418171 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
View source datasets and methodology notes
- 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
Compiled from official public sources by the PlainDoctor editorial team.