Michael Shim, M.D.
NPI 1851503353 · Gastroenterology Physician · Oceanside, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael Shim, M.D. is a Gastroenterology Physician provider in Oceanside, CA (NPI 1851503353).
Provider details
- NPI number
- 1851503353
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A88942 (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
19 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
630 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) |
|---|---|---|
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 118 | $254 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 89 | $94 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 86 | $175 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 75 | $136 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 60 | $119 |
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 |
|---|---|---|
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-C | 323 | 314 |
| Omeprazole | 145 | 58 |
| Pantoprazole Sodium | 56 | 25 |
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 48 | 48 |
| Dexlansoprazolebrand: Dexlansoprazole Dr | 42 | — |
| Linaclotidebrand: Linzess | 37 | 15 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,929 across 90 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
- 2007-05-04
- Last updated
- 2021-02-25
- Certified
- 2021-02-25
Frequently asked questions
- What is Michael Shim's NPI number?
- Michael Shim's National Provider Identifier (NPI) is 1851503353, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael Shim's specialty?
- Michael Shim is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Michael Shim located?
- Michael Shim's practice location on file with NPPES is 3923 Waring Rd Ste a, Oceanside, CA 92056-4499.
- What is Michael Shim's phone number?
- The practice phone number listed in the NPPES registry for Michael Shim is (760) 724-8782.
- Does Michael Shim accept Medicare?
- Michael Shim is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael Shim's NPI active?
- Yes — Michael Shim's NPI (1851503353) is active in the NPPES registry as of the last update on 2021-02-25.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.