NPI registry status
Active
2026 NPPES data Critical Care Medicine (Internal Medicine) Physician NPI 1013004852 M.D.
Verify on CMS → Mark Yamanaka, M.D.
Critical Care Medicine (Internal Medicine) Physician in Oceanside, 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 6,646 in Critical Care Medicine (Internal Medicine) 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
419
Medicare Part D claims · 86 beneficiaries · Critical Care Medicine (Internal Medicine) Physician avg: 1K
Generic prescribing
51%
generic claims · 49% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.3K
55 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Mark Yamanaka, M.D. filed 419 Medicare Part D claims in 2023 as a Critical Care Medicine (Internal Medicine) Physician in Oceanside, California, prescribing 51% generic.
- 419
- Part D claims, 2023
- 51%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥62nd
- pct by Part D claim volume (lower-bound band)
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.
Mark Yamanaka, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
419 ≥ 62nd percentile 62% of 1,370,886 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2023
✓
Board certification likely (heuristic, not verified)
Mark Yamanaka, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 2 hospital affiliations - 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 Mark Yamanaka, M.D.?
Quality data not reportedPrimary specialty
Critical Care Medicine (Internal Medicine) Physician
Medicare Part D claims
419 61% vs specialty avg
Specialty distribution in California
How Critical Care Medicine (Internal Medicine) 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 Critical Care Medicine (Internal Medicine) 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).
Mark Yamanaka, M.D. appears in the CMS NPPES registry as a Critical Care Medicine (Internal Medicine) Physician provider holding M.D. credentials at 3907 WARING RD STE 2, Oceanside, CA, 92056, with a listed phone of (760) 941-0221. NPI 1013004852 was issued on 10/05/2006.
Medicare Part D records for calendar year 2023 show 419 prescription claims written by this provider, covering 86 Medicare beneficiaries and totaling roughly $163K in drug spend, split 49% brand-name and 51% generic by claim count.
Critical Care Medicine (Internal Medicine) Physician is a mid-sized specialty nationwide, with 6,646 enrolled providers across 53 states and an average of 1,069 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 | 1013004852 |
|---|---|
| Specialty | Critical Care Medicine (Internal Medicine) Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 10/05/2006 |
Hospital and facility affiliations
Facilities where Mark Yamanaka, 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.
Cep America - Intensivists PC
Long Beach, CA
Pulmonary Specialists OF North County Inc
Oceanside, 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 Mark Yamanaka, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$1.3K
Largest payer
GlaxoSmithKline, LLC.
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 Mark Yamanaka, M.D.. To verify Mark Yamanaka, 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 · Above average
Mark Yamanaka, M.D. - brand share 49.0%
Critical Care Medicine (Internal Medicine) Physician average
49% brand-name claims vs 51% generic, on 419 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.
419
Total Claims
$163K
Total Drug Cost
86
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 609
- Total Day Supply
- 16,507
- Brand vs Generic
- 49% brand / 51% generic
- Brand Drug Cost
- $156K
- Generic Drug Cost
- $7K
- Antibiotic Claims
- 62
Patient Demographics
- Average Patient Age
- 77.4 years
- Avg HCC Risk Score
- 2.06
- Gender Split
- 63% female / 37% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Mark Yamanaka, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Trelegy Ellipta
Trelegy Ellipta
66 claims
- Roflumilast
Roflumilast
45 claims
- Anoro Ellipta
Anoro Ellipta
39 claims
- Prednisone
Prednisone
38 claims
- Azithromycin
Azithromycin
35 claims
- Albuterol Sulfate …
Albuterol Sulfate Hfa
29 claims
- Incruse Ellipta 24
Incruse Ellipta
24 claims
- Breo Ellipta 17
Breo Ellipta
17 claims
| Drug | Claims |
|---|---|
| Trelegy Ellipta Fluticasone/Umeclidin/Vilanter | 66 |
| Roflumilast | 45 |
| Anoro Ellipta Umeclidinium Brm/Vilanterol Tr | 39 |
| Prednisone | 38 |
| Azithromycin | 35 |
| Albuterol Sulfate Hfa Albuterol Sulfate | 29 |
| Incruse Ellipta Umeclidinium Bromide | 24 |
| Breo Ellipta Fluticasone/Vilanterol | 17 |
| Levofloxacin | 15 |
| Citalopram Hbr Citalopram Hydrobromide | 14 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Critical Care Medicine (Internal Medicine) Physician in CA →
All providers in California →
Compare specialties →
Critical Care Medicine (Internal Medicine) Physician Overview
How Mark Yamanaka, M.D. fits within the Critical Care Medicine (Internal Medicine) Physician landscape nationally.
6,646
Critical Care Medicine (Internal Medicine) Physician Providers in US
53
States with Critical Care Medicine (Internal Medicine) Physician
1,069
Avg Claims per Provider
Mark Yamanaka, M.D.'s 419 claims are below the specialty average of 1,069.
Nearby Critical Care Medicine (Internal Medicine) Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Yamanaka.
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 Critical Care Medicine (Internal Medicine) 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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Medical Specialties Explained
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Understanding Medicare Claims Data
What prescribing data reveals about a provider
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How insurance networks affect your costs
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Frequently Asked Questions
What is Mark Yamanaka, M.D.'s specialty? ▼
Mark Yamanaka, M.D. specializes in Critical Care Medicine (Internal Medicine) Physician and practices in Oceanside, California. Credentials: M.D..
How much does Mark Yamanaka, M.D. prescribe under Medicare Part D? ▼
In 2023, Mark Yamanaka, M.D. wrote 419 Medicare Part D claims totaling $163K in drug costs for 86 beneficiaries.
Where is Mark Yamanaka, M.D. located? ▼
Mark Yamanaka, M.D. is located at 3907 WARING RD STE 2, Oceanside, CA, 92056. Phone: (760) 941-0221.
What is Mark Yamanaka, M.D.'s NPI number? ▼
Mark Yamanaka, M.D.'s National Provider Identifier (NPI) is 1013004852, issued on 10/05/2006.
Does Mark Yamanaka, M.D. prescribe more brand-name or generic drugs? ▼
Mark Yamanaka, M.D.'s prescribing is 49% brand-name and 51% generic drugs by claim count, with $156K in brand drug costs.
How many Critical Care Medicine (Internal Medicine) Physician providers are there in the US? ▼
There are 6,646 Critical Care Medicine (Internal Medicine) Physician providers across 53 states in the US. The average Critical Care Medicine (Internal Medicine) Physician provider writes 1,069 Medicare Part D claims per year.
What drugs does Mark Yamanaka, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Mark Yamanaka, M.D.'s most frequently prescribed drugs include Trelegy Ellipta, Roflumilast, Anoro Ellipta. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Mark Yamanaka, M.D. accept Medicare? ▼
Mark Yamanaka, M.D. appears in CMS Medicare data with 419 Part D claims and 86 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Mark Yamanaka, M.D.'s credentials? ▼
Mark Yamanaka, M.D.'s NPI is 1013004852 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
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.