Dr. Mark A. Casillas
- Gender: Male
- Experience: 15 years
- Graduation year: 2006
- Sole propriator: Yes
- NPI: 1245458082
Dr. Mark A. Casillas JR. M.D.
Colorectal Surgeon
He is located at 1934 Alcoa Highway Bldg D, Suite 370 in Knoxville, TN 37920. Can help patients with the following: Cyst, Esophageal Cancer, Lymphedema, Pancreatitis, Pilonidal Cyst, Sebaceous Cyst. His National Provider Identifier (NPI) number is 1245458082. Appointment can be made via the phone number (865) 305-5335. He is affiliated with 3 practices and 1 hospitals.
Conditions treated
Dr. Mark A. Casillas, being an colorectal surgeon, treats the following conditions. Please be advised that this list may not be complete. For the full list of conditions treated, consult directly with Dr. Mark A. Casillas.
- Achalasia
- Anal Fissure
- Appendicitis
- Boils
- Cancer
- Colon Cancer
- Crohn's Disease
- Cyst
- Diverticulosis
- Enlarged Spleen
- Esophageal Cancer
- Gallstones
- Gangrene
- Heart Disease
- Hemorrhoids
- Hernia
- Inflammatory Bowel Disease (IBD)
- Lymphedema
- Pancreatitis
- Peptic Ulcer
- Pilonidal Cyst
- Sebaceous Cyst
- Ulcerative Colitis
Procedures Performed by Dr. Mark A. Casillas
ACA Marketplace (Obamacare/HealthCare.gov) plan networks
Insurers selling ACA Marketplace (HealthCare.gov) plans list Dr. Mark A. Casillas as in-network for the following 2026 plans.
Health plans
BlueCross BlueShield of Tennessee
Network data as of Aug 25, 2026, as reported by the insurer.
Show all 12 plans from BlueCross BlueShield of Tennessee
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| BlueCross B15E $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Bronze | Blue Network E | Accepting new patients |
| BlueCross B16E $50 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Expanded Bronze | Blue Network E | Accepting new patients |
| BlueCross B16S $50 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Expanded Bronze | Blue Network S | Accepting new patients |
| BlueCross B17E $0 virtual care from Teladoc Health® + Adult Dental (8 plan variants) | EPO · Bronze | Blue Network E | Accepting new patients |
| BlueCross B19E $60 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Expanded Bronze | Blue Network E | Accepting new patients |
| BlueCross G08E $30 PCP Copay + $0 virtual care from Teladoc Health ® (8 plan variants) | EPO · Gold | Blue Network E | Accepting new patients |
| BlueCross G08S $30 PCP Copay + $0 virtual care from Teladoc Health ® (8 plan variants) | EPO · Gold | Blue Network S | Accepting new patients |
| BlueCross S26E $40 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Silver | Blue Network E | Accepting new patients |
| BlueCross S26S $40 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Silver | Blue Network S | Accepting new patients |
| BlueCross S27E $60 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Silver | Blue Network E | Accepting new patients |
| BlueCross S29E $60 PCP Copay + $0 virtual care from Teladoc Health® + Adult Dental (8 plan variants) | EPO · Silver | Blue Network E | Accepting new patients |
| BlueCross S34E $45 PCP Copay + $0 virtual care from Teladoc Health® (8 plan variants) | EPO · Silver | Blue Network E | Accepting new patients |
Cigna Healthcare
Network data as of Sep 15, 2026, as reported by the insurer.
Show all 10 plans from Cigna Healthcare
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Connect Bronze 7500 Indiv Med Deductible | EPO · Bronze | Preferred | Accepting new patients |
| Connect Bronze 8500 Indiv Med Deductible | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Connect Bronze CMS Standard | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Connect Gold 1500 Indiv Med Deductible | EPO · Gold | Preferred | Accepting new patients |
| Connect Gold CMS Standard | EPO · Gold | Preferred | Accepting new patients |
| Connect myDiabetesCare Bronze | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Connect myDiabetesCare Silver | EPO · Silver | Preferred | Accepting new patients |
| Connect Silver 3000 Indiv Med Deductible | EPO · Silver | Preferred | Accepting new patients |
| Connect Silver 4500 Indiv Med Deductible | EPO · Silver | Preferred | Accepting new patients |
| Connect Silver CMS Standard | EPO · Silver | Preferred | Accepting new patients |
Oscar Insurance Company
Network data as of Sep 15, 2026, as reported by the insurer.
Show all 15 plans from Oscar Insurance Company
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Bronze Classic Standard | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Elite + PCP Saver Plus | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple Breathe Easy with Enhanced COPD Benefits | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple Chronic Care CKM | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple Diabetes | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Gold Classic Standard | EPO · Gold | Preferred | Accepting new patients |
| Gold Elite | EPO · Gold | Preferred | Accepting new patients |
| Silver Classic | EPO · Silver | Preferred | Accepting new patients |
| Silver Classic Standard | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Breathe Easy with Enhanced COPD Benefits | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Chronic Care CKM | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Diabetes | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple PCP Saver | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Women's Health with Menopause Benefits | EPO · Silver | Preferred | Accepting new patients |
UnitedHealthcare
Network data as of Sep 16, 2026, as reported by the insurer.
Show all 12 plans from UnitedHealthcare
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| UHC Bronze Copay Focus (Virtual Urgent Care, No Referrals) | EPO · Expanded Bronze | Non Preferred | Accepting new patients |
| UHC Bronze Copay Focus + (Virtual Urgent Care, Dental + Vision, No Referrals) | EPO · Expanded Bronze | Non Preferred | Accepting new patients |
| UHC Bronze Essential (No Referrals) | EPO · Bronze | Non Preferred | Accepting new patients |
| UHC Bronze Standard (No Referrals) | EPO · Expanded Bronze | Non Preferred | Accepting new patients |
| UHC Gold Advantage (Virtual Urgent Care, No Referrals) | EPO · Gold | Non Preferred | Accepting new patients |
| UHC Gold Advantage + (Virtual Urgent Care, Dental + Vision, No Referrals) | EPO · Gold | Non Preferred | Accepting new patients |
| UHC Gold Copay Focus (Virtual Urgent Care, No Referrals) | EPO · Gold | Non Preferred | Accepting new patients |
| UHC Gold Standard (No Referrals) | EPO · Gold | Non Preferred | Accepting new patients |
| UHC Silver Advantage (Virtual Urgent Care, No Referrals) | EPO · Silver | Non Preferred | Accepting new patients |
| UHC Silver Advantage + (Virtual Urgent Care, Dental + Vision, No Referrals) | EPO · Silver | Non Preferred | Accepting new patients |
| UHC Silver Copay Focus (Virtual Urgent Care, No Referrals) | EPO · Silver | Non Preferred | Accepting new patients |
| UHC Silver Standard (No Referrals) | EPO · Silver | Non Preferred | Accepting new patients |
This covers ACA Marketplace plans only, as reported by each insurer. It does not include employer, Medicare Advantage, or state-run exchange plans, and a plan missing from this list does not mean Dr. Mark A. Casillas is out of network. Insurer directories can be out of date, so always confirm with the insurer and the office before your visit.
Medicare Enrollment
Dr. Mark A. Casillas is enrolled to bill Medicare as a Practitioner - Colorectal Surgery (proctology) (also registered under: Practitioner - General Surgery) .
Bills through: University Health System, Inc.
Based on Medicare's public enrollment records as of Jul 17, 2026. This reflects Medicare fee-for-service enrollment only and says nothing about other insurance, quality, outcomes, or board certification.
Payments received
Drug payment
| Cubist Pharmaceuticals | $5714 |
| Intuitive Surgical | $1810 |
| Applied Medical | $520 |
Other
| Promotional Speaking or Service | $5700 |
| Food and Beverage | $3409 |
| Travel and Lodging | $1434 |
| Other | $11 |
Studies
Graduated in 2006Additional Specialities
- Surgeon
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Questions & Answers
Does Dr. Mark A. Casillas have affiliation with practices?
Dr. Mark A. Casillas is affiliated with Women's Care Group. For the full list of practices see this list.
Does Dr. Mark A. Casillas accept patients with Cigna Healthcare?
Yes, Dr. Mark A. Casillas is listed in-network for Cigna Healthcare through the ACA Marketplace (Obamacare/HealthCare.gov). See the Marketplace plans section for details.
What conditions does Dr. Mark A. Casillas treat?
Dr. Mark A. Casillas provides treatment for Cyst, Esophageal Cancer, Lymphedema, Pancreatitis, Pilonidal Cyst, Sebaceous Cyst. For the full list see this list.
Where can you meet with Dr. Mark A. Casillas?
Dr. Mark A. Casillas's office is located at 1934 Alcoa Highway Bldg D, Suite 370 in Knoxville, TN 37920.
Has Dr. Mark A. Casillas affiliation with hospitals?
Dr. Mark A. Casillas is affiliated with UNIVERSITY OF TN MEDICAL CENTER.