Matthew Nienaber, D.O.
NPI 1033535182 · Internal Medicine Physician · Santa Monica, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Matthew Nienaber, D.O. is a Internal Medicine Physician provider in Santa Monica, CA (NPI 1033535182).
Provider details
- NPI number
- 1033535182
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- D.O.
- Sex
- Male
- Sole proprietor
- No
- License
- 20A14759 (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
12 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
584 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 | 163 | $139 |
| 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 | 128 | $17 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 121 | $9 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 63 | $195 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 40 | $141 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 68 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 202 | 60 |
| Gabapentin | 94 | 24 |
| Levothyroxine Sodium | 87 | 23 |
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 80 | 11 |
| Amlodipine Besylate | 79 | 26 |
| Metformin Hcl | 76 | 22 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$329 across 14 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
Additional practice locations (1)
- 355 Abbott St Ste 100Salinas, CA 93901-4484Phone: (831) 751-7070Fax: (831) 751-7050
Registry dates
- Enumerated
- 2014-03-13
- Last updated
- 2026-05-28
- Certified
- 2026-05-28
Frequently asked questions
- What is Matthew Nienaber's NPI number?
- Matthew Nienaber's National Provider Identifier (NPI) is 1033535182, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Matthew Nienaber's specialty?
- Matthew Nienaber is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Matthew Nienaber located?
- Matthew Nienaber's practice location on file with NPPES is 1821 Wilshire Blvd Ste 100, Santa Monica, CA 90403-5627.
- What is Matthew Nienaber's phone number?
- The practice phone number listed in the NPPES registry for Matthew Nienaber is (310) 575-3100.
- Does Matthew Nienaber accept Medicare?
- Matthew Nienaber is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Matthew Nienaber's NPI active?
- Yes — Matthew Nienaber's NPI (1033535182) is active in the NPPES registry as of the last update on 2026-05-28.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.