Eric Day, MD
NPI 1316443534 · Hospitalist Physician · Santa Cruz, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Eric Day, MD is a Hospitalist Physician provider in Santa Cruz, CA (NPI 1316443534).
Provider details
- NPI number
- 1316443534
- Entity type
- Individual
- Primary specialty
- Hospitalist PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A166078 (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
8 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
1,008 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 Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 520 | $127 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 211 | $84 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 194 | $124 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 60 | $185 |
| Prolonged Hospital Inpatient Or Observation Care Evaluation and Management Service(s) Beyond the Total Time for the Primary Service (when the Primary Service Has Been Selected Using Time on the Date of the Primary Service); Each Additional 15 Minutes By ThG0316 | 23 | $33 |
Typical Medicare-allowed amounts for these services range $33–$185 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, 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 · 3 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Amoxicillin/Potassium Clavbrand: Amoxicillin-Clavulanate Potass | 17 | 16 |
| Metoprolol Succinate | 15 | 11 |
| Atorvastatin Calcium | 12 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-04-05
- Last updated
- 2023-07-18
- Certified
- 2022-09-28
Frequently asked questions
- What is Eric Day's NPI number?
- Eric Day's National Provider Identifier (NPI) is 1316443534, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Eric Day's specialty?
- Eric Day is listed in the NPPES registry with a primary specialty of Hospitalist Physician (Allopathic & Osteopathic Physicians).
- Where is Eric Day located?
- Eric Day's practice location on file with NPPES is 1595 Soquel Dr Ste 400, Santa Cruz, CA 95065-1724.
- What is Eric Day's phone number?
- The practice phone number listed in the NPPES registry for Eric Day is (831) 475-1111.
- Does Eric Day accept Medicare?
- Eric Day is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Eric Day's NPI active?
- Yes — Eric Day's NPI (1316443534) is active in the NPPES registry as of the last update on 2023-07-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.