Irvin Lien, MD
NPI 1124654272 · Hospitalist Physician · Redwood City, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Irvin Lien, MD is a Hospitalist Physician provider in Redwood City, CA (NPI 1124654272).
Provider details
- NPI number
- 1124654272
- Entity type
- Individual
- Primary specialty
- Hospitalist PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A180133 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
6 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
11 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 11 | $144 |
Typical Medicare-allowed amounts for these services range $144–$144 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 11 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Furosemide | 49 | 32 |
| Atorvastatin Calcium | 36 | 20 |
| Cefpodoxime Proxetil | 35 | 35 |
| Prednisone | 21 | 21 |
| Metoprolol Tartrate | 19 | — |
| Doxycycline Monohydrate | 17 | 17 |
| Pantoprazole Sodium | 15 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2020-03-20
- Last updated
- 2023-07-02
- Certified
- 2023-07-02
Frequently asked questions
- What is Irvin Lien's NPI number?
- Irvin Lien's National Provider Identifier (NPI) is 1124654272, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Irvin Lien's specialty?
- Irvin Lien is listed in the NPPES registry with a primary specialty of Hospitalist Physician (Allopathic & Osteopathic Physicians).
- Where is Irvin Lien located?
- Irvin Lien's practice location on file with NPPES is 1100 Veterans Blvd, Redwood City, CA 94063-2037.
- What is Irvin Lien's phone number?
- The practice phone number listed in the NPPES registry for Irvin Lien is (650) 299-2000.
- Does Irvin Lien accept Medicare?
- Irvin Lien is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Irvin Lien's NPI active?
- Yes — Irvin Lien's NPI (1124654272) is active in the NPPES registry as of the last update on 2023-07-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.