DR. RONALD MARK TILSEN M.D.
NPI 1801852280
Internal Medicine in Newport Beach, CA

Q: What is Ronald Tilsen's NPI number?

The NPI number for Ronald Tilsen is 1801852280. It was assigned to this individual provider in the NPPES registry on April 25, 2006.

Q: What is Ronald Tilsen's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Q: When was this NPI record last updated?

The NPPES record for Ronald Tilsen was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since April 25, 2006PECOS Enrolled

400 NEWPORT CENTER DR, SUITE 608, NEWPORT BEACH, CA 92660(949) 644-3559(949) 718-6729 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: November 01, 2026.

On this page

About Dr. Ronald Mark Tilsen M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. RONALD MARK TILSEN M.D. (NPI 1801852280) is an individual internal medicine provider in Newport Beach, California, licensed in California (G34508) and active in the NPI registry since April 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1801852280

Entity TypeIndividualMale

Primary Taxonomy207R00000X

Provider Legal NameDR. RONALD MARK TILSENCredential: M.D.

Location Address400 NEWPORT CENTER DR, SUITE 608Newport Beach, CA 92660-7601

Mailing Address400 Newport Center Dr, Suite 608Newport Beach, CA 92660-7601 · (949) 644-3559 · Fax (949) 718-6729

Phone(949) 644-3559

Fax(949) 718-6729

Sole ProprietorNo

Enumeration DateApril 25, 2006

Last NPPES UpdateJuly 13, 2026

✔ NPI 1801852280 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207R00000X

License✔ Licensed in CA · G34508

Definition

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

400 NEWPORT CENTER DR, Newport Beach, CA 92660

Open in Google Maps ↗

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Ronald Mark Tilsen M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show Ronald Tilsen reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Newport Center Medical Group

Same address

Endocrinology, Diabetes & Metabolism

400 NEWPORT CENTER DR, SUITE 504
Newport Beach, CA 92660

Reassigned Medicare billing, California enrollment
9 clinicians in this Medicare group

NPI 1467478008 (949) 720-4920

Uc Regents

12 mi

Allergy & Immunology

101 THE CITY DR S
Orange, CA 92868

Reassigned Medicare billing, California enrollment
525 clinicians in this Medicare group

NPI 1003864174 (714) 456-8068

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92660 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$142.39 typical visit price

range $62.96 – $187.60

Typical copayment $35.59 (range $15.74 – $46.90)

Most-billed visit code 99204

Established Patient

$109.96 typical visit price

range $20.84 – $153.61

Typical copayment $27.49 (range $5.21 – $38.40)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

KELLI JUNKER DDS

Dentist (General Practice)

400 NEWPORT CENTER DR, SUITE 708
NEWPORT BEACH, CA 92660

Orange County (949) 640-2970

DR. KYUYOUNG LIM D.M.D., M.P.H.

Dentist (Periodontics)

400 NEWPORT CENTER DR, 208
NEWPORT BEACH, CA 92660

Orange County (949) 718-0208

DR. ARTHUR JOHN HELLIWELL D.D.S.

Dentist

400 NEWPORT CENTER DR, SUITE 304
NEWPORT BEACH, CA 92660

Orange County (949) 760-6022

ROXANNE GISELLE G LIM MD

Internal Medicine (Gastroenterology)

400 NEWPORT CENTER DR, SUITE 609
NEWPORT BEACH, CA 92660

Orange County (949) 760-0398

ANNA VALERIE OTTAKA M.D.

Internal Medicine

400 NEWPORT CENTER DR, STE 608
NEWPORT BEACH, CA 92660

Orange County (949) 720-4920

JON M. GRAZER MD MPH INC

Plastic Surgery

400 NEWPORT CENTER DR, 302
NEWPORT BEACH, CA 92660

Orange County (949) 644-1240

JAMES E BARBER MD PROFESSIONAL CORPORATION

Clinic/Center (Medical Specialty)

400 NEWPORT CENTER DR, SUITE 409
NEWPORT BEACH, CA 92660

Orange County (949) 760-8040

JAMES L WINTERTON DDS, INC.

Clinic/Center (Dental)

400 NEWPORT CENTER DR, SUITE 304
NEWPORT BEACH, CA 92660

Orange County (949) 760-6022

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Ronald Tilsen's NPI number?

The NPI number for Ronald Tilsen is 1801852280. It was assigned to this individual provider in the NPPES registry on April 25, 2006.

Where is Ronald Tilsen located?

Ronald Tilsen practices at 400 Newport Center Dr Suite 608, Newport Beach, CA 92660. The listed phone number is (949) 644-3559.

What is Ronald Tilsen's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Ronald Tilsen enrolled in Medicare?

Yes. Ronald Tilsen is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Ronald Tilsen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Ronald Tilsen reassigns Medicare benefits to 2 organizations: Newport Center Medical Group (Newport Beach, CA) and Uc Regents (Orange, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Ronald Tilsen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Ronald Tilsen was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.