Nevada County's Surgical Specialists

Advanced General & Trauma Surgery
Close to Home in Grass Valley

Compassionate, board-certified surgical care for the Sierra Nevada community. From emergency interventions to planned procedures, Dr. Thielen delivers the expertise you deserve with the personal attention your health demands.

Call (530) 271-7262 View Services
Board Certified
Grass Valley, CA
Accepting New Patients
Clinical Expertise

Comprehensive Surgical Services

Providing a full spectrum of surgical care to the Grass Valley community, from routine procedures to complex trauma interventions.

General Surgery

Expert treatment for abdominal conditions including hernias, gallbladder disease, and gastrointestinal disorders using both open and minimally invasive techniques.

Trauma Surgery

Rapid, decisive emergency surgical care for acute injuries. As a designated trauma specialist, Dr. Thielen manages complex trauma cases with precision and urgency.

Minimally Invasive

Advanced laparoscopic and endoscopic procedures that reduce recovery time, minimize scarring, and lower the risk of complications compared to traditional open surgery.

Pre & Post-Operative Care

Thorough evaluations before surgery and comprehensive follow-up care after procedures to ensure optimal healing and outcomes for every patient.

Elective Procedures

Planning and performing scheduled surgical interventions with clear communication, realistic expectations, and personalized care plans tailored to your needs.

Patient Education

We believe an informed patient is an empowered patient. Dr. Thielen takes time to explain diagnoses, procedures, and recovery protocols in plain language.

Medical facility in Grass Valley
About Dr. Thielen

Dedicated to Surgical Excellence in the Sierra Nevada

Mark R. Thielen, MD is a board-certified general and trauma surgeon committed to serving the medical needs of Grass Valley and the surrounding Nevada County communities.

With extensive training in both general surgical principles and acute trauma management, Dr. Thielen brings a comprehensive skill set to every case. Whether treating a complex hernia, performing gallbladder removal, or responding to emergency trauma, he combines technical precision with a patient-centered approach.

Located on North Auburn Street, the practice is conveniently positioned to serve residents from Grass Valley, Nevada City, and the broader Gold Country region.

Board Certified
General Surgery
Trauma Surgery
Insurance & Patients

Insurance & New Patients

We accept most major insurance plans. Please contact our office to verify coverage for your specific procedure. New patients are welcome.

  • Major Insurance Plans Accepted
  • Medicare & Medicaid
  • Worker's Compensation
  • Self-Pay Options Available

Please call to confirm your specific plan is accepted.

Schedule an Appointment

Ready to take the next step? Contact us to schedule a consultation.

Visit Us

Conveniently Located in Downtown Grass Valley

Address

120 N Auburn St
Grass Valley, CA 95945-6277

Office Hours

Monday – Friday
8:00 AM – 5:00 PM

Is this your business?This is my business