Mark Casillas, M.D.
NPI 1245458082 · Surgery Physician · Knoxville, TN
Enrolled with Medicare as Practitioner - Colorectal Surgery (proctology) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Casillas, M.D. is a Surgery Physician provider in Knoxville, TN (NPI 1245458082).
Provider details
- NPI number
- 1245458082
- Entity type
- Individual
- Primary specialty
- Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- LP00968 (RI)
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 tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
271 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Diagnostic Exam of Anus Using an Endoscope46600 | 55 | $108 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 45 | $83 |
| Removal of Polyps Or Growths of Large Bowel Using a Flexible Endoscope With Electrical Cautery45384 | 36 | $132 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 36 | $106 |
| Diagnostic Exam of Rectum and Lower Large Bowel Using an Endoscope45300 | 21 | $115 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ondansetron Hcl | 60 | 54 |
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 59 | 57 |
| Metronidazole | 37 | 37 |
| Ciprofloxacin Hcl | 27 | 27 |
| Sod Sulf/Pot Chloride/Mag Sulfbrand: Sutab | 15 | 15 |
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$554 across 15 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-04-24
- Last updated
- 2014-02-04
Frequently asked questions
- What is Mark Casillas's NPI number?
- Mark Casillas's National Provider Identifier (NPI) is 1245458082, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Casillas's specialty?
- Mark Casillas is listed in the NPPES registry with a primary specialty of Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Casillas located?
- Mark Casillas's practice location on file with NPPES is 1934 Alcoa Highway, Knoxville, TN 37920.
- What is Mark Casillas's phone number?
- The practice phone number listed in the NPPES registry for Mark Casillas is (865) 305-5335.
- Does Mark Casillas accept Medicare?
- Mark Casillas is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Casillas's NPI active?
- Yes — Mark Casillas's NPI (1245458082) is active in the NPPES registry as of the last update on 2014-02-04.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.