Quick answers
- Which hospitals does John D. Day work at?
- Medicare's official clinician data lists John D. Day at 1 hospital: St Mark's Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John D. Day see patients?
- Medicare's clinician data lists 1 practice location in Salt Lake City, UT. Call before your visit to confirm the address.
- What is John D. Day's specialty?
- Medicare lists Cardiac Electrophysiology as the primary specialty, and also Internal Medicine.
- Does John D. Day accept Medicare assignment?
- Yes. Medicare's clinician data says John D. Day accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- Does John D. Day offer telehealth?
- Medicare's clinician data says John D. Day offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for John D. Day?
- (801) 266-3418, as listed in official Medicare / NPI Registry data.
- What is John D. Day's NPI number?
- 1811965122. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John D. Day works
Medicare's Facility Affiliation Data lists John D. Day at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- St Mark's HospitalSalt Lake City, UT · Acute Care Hospital · CCN 460047
Practice locations
Addresses where John D. Day is enrolled with Medicare (CMS data updated 2026-10-02).
- 1160 E 3900, Suite 2000Salt Lake City, UT 84124 (801) 266‑3418
Group practices
Medicare enrollment lists John D. Day as a member of this group (CMS data updated 2026-10-02).
- Mountainstar Cardiology St Marks LLC42 clinicians in the group
Specialties
- Cardiac Electrophysiologyprimary
- Internal Medicinealso
Other cardiac electrophysiologists in Salt Lake City
Clinicians with the same Medicare primary specialty in Salt Lake City, UT — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Johns Hopkins University School Of Medicine |
| Graduation year | 1995 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1811965122 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians