Karen Johnston, MD
NPI 1326518325 · General Practice Physician · Palo Alto, CA
Enrolled with Medicare as Practitioner - Pathology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Karen Johnston, MD is a General Practice Physician provider in Palo Alto, CA (NPI 1326518325).
Provider details
- NPI number
- 1326518325
- Entity type
- Individual
- Primary specialty
- General Practice PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- G67445 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
7 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
1,630 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) |
|---|---|---|
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, 20 Minutes Or More99308 | 924 | $92 |
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, at Least 10 Minutes99307 | 353 | $50 |
| Initial Nursing Facility Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99304 | 158 | $97 |
| Subsequent Nursing Facility Care With Moderate Level of Medical Decision Making, Per Day, If Using Time, at Least 30 Minutes99309 | 85 | $132 |
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, 20 Minutes Or More99308 | 72 | $92 |
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, at Least 10 Minutes |
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-12-03
- Last updated
- 2022-01-28
- Certified
- 2022-01-28
Frequently asked questions
- What is Karen Johnston's NPI number?
- Karen Johnston's National Provider Identifier (NPI) is 1326518325, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Karen Johnston's specialty?
- Karen Johnston is listed in the NPPES registry with a primary specialty of General Practice Physician (Allopathic & Osteopathic Physicians).
- Where is Karen Johnston located?
- Karen Johnston's practice location on file with NPPES is 478 E Charleston Rd, Palo Alto, CA 94306-4235.
- What is Karen Johnston's phone number?
- The practice phone number listed in the NPPES registry for Karen Johnston is (650) 380-9149.
- Does Karen Johnston accept Medicare?
- Karen Johnston is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Karen Johnston's NPI active?
- Yes — Karen Johnston's NPI (1326518325) is active in the NPPES registry as of the last update on 2022-01-28.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.