Matthew Nienaber MD

Matthew Nienaber, D.O.

Internal Medicine

Not Accepting New Patients

About Matthew Nienaber, D.O. 

Born on the West Coast, native of the Bay Area, Matthew K. Nienaber, D.O., was raised in the Pacific Northwest with one foot in the sand and one in the water.  

Caring and compassionate, Dr. Nienaber works with his patients to provide individualized healthcare. With a strong passion for helping the underserved, he participates in medical missions to Africa, South America, and Mexico.  

Dr. Nienaber earned his medical degree at the Western University College of Osteopathic Medicine of the Pacific in Pomona, California. He completed his internship and residency at the Arrowhead Regional Medical Center in Colton, California.  

Dr. Nienaber’s patients say he is an excellent practitioner, is courteous and professional, and puts you at ease. They feel truly fortunate to have Dr. Nienaber as their primary physician.  

Dr. Nienaber is a former competitive dragon boat racer. He enjoys playing piano and bass, as well as restoring classic British race cars.  

I feel like my Doctor really cares about my health

Real Patient
Matthew Nienaber

Selected: Up Next:

Matthew K. Nienaber, D.O.
Family & Internal Medicine

Selected: Up Next:

Family & Internal Medicine
01 / 02

Locations

1821 Wilshire Blvd., Suite 100,
Santa Monica, CA 90403
(310) 575-3100

Education

Medical School
Western University College of Osteopathic Medicine of the Pacific

Internship
Arrowhead Regional Medical Center, Colton, CA

Residency
Arrowhead Regional Medical Center, Colton, CA

Languages

Spanish

child checkup

Reviews

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As part of ensuring you have a positive experience with Providence, our online provider directory includes ratings and patient comments for select providers. More about our survey.

  • 4.9
  • 171 Reviews
  • 454 Comments
  • 5
07/24/2026

DR. Nienaber is a gem. An authentic and caring physician. Listen's well and discusses treatment options.

Providence Patient
  • 5
07/24/2026

Excellent doctor

Providence Patient
  • 5
07/23/2026

I have recommended Dr Nienaber several times on Nextdoor.

Providence Patient
  • 5
07/23/2026

Dr Neinaber is the best! Always listens, provides information if needed and very easy to communicate with, really like him!

Providence Patient
  • 5
07/16/2026

Very helpful!!!

Providence Patient
  • 5
07/07/2026

Very happy with my Doctor!

Providence Patient
  • 5
06/28/2026

I so appreciate how he cares and listens. Compassion, sense of humor and real connection too with great knowledge. I am in a good space with my mental health and physical health and Dr. Neinaber has been part of my improvement.

Providence Patient
  • 5
06/26/2026

Dr. Nienaber is very competent helpful and friendly.

Providence Patient
  • 5
06/26/2026

Best doctor

Providence Patient
  • 5
06/23/2026

He's the best

Providence Patient