Karen Spizer, MD
NPI 1043384365 · Internal Medicine Physician · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Karen Spizer, MD is a Internal Medicine Physician provider in Walnut Creek, CA (NPI 1043384365).
Provider details
- NPI number
- 1043384365
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- A76234 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 25 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 44 | 18 |
| Gabapentin | 36 | — |
| Furosemide | 34 | 11 |
| Potassium Chloride | 33 | 11 |
| Quetiapine Fumarate | 30 | — |
| Oxycodone Hcl | 26 | — |
| Trazodone Hcl |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-20
- Last updated
- 2021-12-09
Frequently asked questions
- What is Karen Spizer's NPI number?
- Karen Spizer's National Provider Identifier (NPI) is 1043384365, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Karen Spizer's specialty?
- Karen Spizer is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Karen Spizer located?
- Karen Spizer's practice location on file with NPPES is 1425 S Main St, Walnut Creek, CA 94596-5318.
- What is Karen Spizer's phone number?
- The practice phone number listed in the NPPES registry for Karen Spizer is (925) 295-4000.
- Does Karen Spizer accept Medicare?
- Karen Spizer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Karen Spizer's NPI active?
- Yes — Karen Spizer's NPI (1043384365) is active in the NPPES registry as of the last update on 2021-12-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.