Mark Lewis, MD
NPI 1891985800 · Internal Medicine Physician · Mountain View, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Lewis, MD is a Internal Medicine Physician provider in Mountain View, CA (NPI 1891985800).
Provider details
- NPI number
- 1891985800
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- A96667 (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
18 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
1,763 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 Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 469 | $105 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 441 | $82 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 209 | $205 |
| Established Patient Office Or Other Outpatient Visit With Straightforward Medical Decision Making, If Using Time, 10 Minutes Or More99212 | 194 | $66 |
| Telephone Medical Discussion With Physician, 5-10 Minutes99441 | 192 | $62 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 95 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Amlodipine Besylate | 323 | 85 |
| Levothyroxine Sodium | 281 | 71 |
| Atorvastatin Calcium | 281 | 71 |
| Rosuvastatin Calcium | 234 | 68 |
| Metformin Hcl | 210 | 57 |
| Hydrochlorothiazide | 147 | 39 |
| Metoprolol Succinate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$266 across 3 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
- 2007-07-26
- Last updated
- 2009-12-15
Frequently asked questions
- What is Mark Lewis's NPI number?
- Mark Lewis's National Provider Identifier (NPI) is 1891985800, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Lewis's specialty?
- Mark Lewis is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Lewis located?
- Mark Lewis's practice location on file with NPPES is 2204 Grant Rd Ste 105, Mountain View, CA 94040-3877.
- What is Mark Lewis's phone number?
- The practice phone number listed in the NPPES registry for Mark Lewis is (650) 967-8890.
- Does Mark Lewis accept Medicare?
- Mark Lewis is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Lewis's NPI active?
- Yes — Mark Lewis's NPI (1891985800) is active in the NPPES registry as of the last update on 2009-12-15.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.