John Mesmer, M.D.
NPI 1518914951 · Emergency Medicine Physician · Oak Ridge, TN
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Mesmer, M.D. is a Emergency Medicine Physician provider in Oak Ridge, TN (NPI 1518914951).
Provider details
- NPI number
- 1518914951
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 020154 (TN)
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
20 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
734 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) |
|---|---|---|
| Emergency Department Visit With High Level of Medical Decision Making99285 | 447 | $161 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 211 | $111 |
| Critical Care, First 30-74 Minutes99291 | 47 | $195 |
| Emergency Department Visit With Low Level of Medical Decision Making99283 | 29 | $65 |
Typical Medicare-allowed amounts for these services range $65–$195 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote 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 · 12 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Prednisone | 56 | 56 |
| Ondansetronbrand: Ondansetron Odt | 44 | 41 |
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 43 | 43 |
| Cephalexin | 37 | 37 |
| Oxycodone Hcl/Acetaminophenbrand: Oxycodone-Acetaminophen | 35 | 34 |
| Cefdinir | 18 | 18 |
| Tramadol Hcl |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-30
- Last updated
- 2007-11-29
Frequently asked questions
- What is John Mesmer's NPI number?
- John Mesmer's National Provider Identifier (NPI) is 1518914951, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Mesmer's specialty?
- John Mesmer is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John Mesmer located?
- John Mesmer's practice location on file with NPPES is 990 Oak Ridge Tpke, Oak Ridge, TN 37830-6976.
- What is John Mesmer's phone number?
- The practice phone number listed in the NPPES registry for John Mesmer is (865) 481-1000.
- Does John Mesmer accept Medicare?
- John Mesmer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Mesmer's NPI active?
- Yes — John Mesmer's NPI (1518914951) is active in the NPPES registry as of the last update on 2007-11-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.