Marc-Alan Iwahashi, M.D.,
NPI 1235123985 · Family Medicine Physician · Cupertino, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Marc-Alan Iwahashi, M.D., is a Family Medicine Physician provider in Cupertino, CA (NPI 1235123985).
Provider details
- NPI number
- 1235123985
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.,
- Sex
- Male
- Sole proprietor
- No
- License
- G68531 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
20 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
753 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 187 | $157 |
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'SG2211 | 165 | $19 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 155 | $161 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 113 | $109 |
| Online Digital Evaluation and Management Service for an Established Patient for Up to 7 Days, Total Time 5-10 Minutes99421 | 30 | $18 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 65 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Amlodipine Besylate | 240 | 69 |
| Atorvastatin Calcium | 237 | 80 |
| Levothyroxine Sodium | 176 | 47 |
| Metformin Hcl | 151 | 53 |
| Losartan Potassium | 147 | 53 |
| Rosuvastatin Calcium | 135 | 48 |
| Simvastatin |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$48 across 2 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-09-08
- Last updated
- 2012-01-05
Frequently asked questions
- What is Marc-Alan Iwahashi's NPI number?
- Marc-Alan Iwahashi's National Provider Identifier (NPI) is 1235123985, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Marc-Alan Iwahashi's specialty?
- Marc-Alan Iwahashi is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Marc-Alan Iwahashi located?
- Marc-Alan Iwahashi's practice location on file with NPPES is 20555 Prospect Rd, Cupertino, CA 95014-5212.
- What is Marc-Alan Iwahashi's phone number?
- The practice phone number listed in the NPPES registry for Marc-Alan Iwahashi is (408) 253-5811.
- Does Marc-Alan Iwahashi accept Medicare?
- Marc-Alan Iwahashi is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Marc-Alan Iwahashi's NPI active?
- Yes — Marc-Alan Iwahashi's NPI (1235123985) is active in the NPPES registry as of the last update on 2012-01-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.