DR. STEPHAN ROBERT GRIGORIAN M.D.
NPI 1821129057
Pathology - Anatomic Pathology & Clinical Pathology in Corona, CA

Active since March 08, 2007PECOS EnrolledAccepts Medicare Assignment
800 S MAIN ST, CORONA, CA 92882(858) 877-0267 Get Directions Write a Review

NPPES record last updated: August 29, 2022. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Dr. Stephan Robert Grigorian M.d. NPPES

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

DR. STEPHAN ROBERT GRIGORIAN M.D. (NPI 1821129057) is an individual anatomic pathology & clinical pathology provider in Corona, California, licensed in California (A88170) and active in the NPI registry since March 2007. He is enrolled in Medicare PECOS and is a graduate of Other (1993).

NPPES Registry Identity

NPI1821129057
Entity TypeIndividualMale
Primary Taxonomy207ZP0102X
Provider Legal NameDR. STEPHAN ROBERT GRIGORIANCredential: M.D.
Location Address800 S MAIN STCorona, CA 92882-3420
Mailing AddressPo Box 4544Mission Viejo, CA 92690-4544 · (314) 849-3535
Sole ProprietorYes
Medical School CMSOtherGraduated 1993
Enumeration DateMarch 8, 2007
Last NPPES UpdateAugust 29, 2022
NPPES CertifiedAugust 29, 2022
✔ NPI 1821129057 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPathology · Anatomic Pathology & Clinical PathologyAllopathic & Osteopathic Physicians
Taxonomy Code207ZP0102X
License✔ Licensed in CA · A88170
Definition
A pathologist deals with the causes and nature of disease and contributes to diagnosis, prognosis and treatment through knowledge gained by the laboratory application of the biologic, chemical and physical sciences. A pathologist uses information gathered from the microscopic examination of tissue specimens, cells and body fluids, and from clinical laboratory tests on body fluids and secretions for the diagnosis, exclusion and monitoring of disease.
800 S MAIN ST, Corona, CA 92882

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Stephan Robert Grigorian M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID9931296498
PECOS Enrollment IDI20071030000589
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 Reassignment

Medicare enrollment records show Stephan Grigorian reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Anatomic Pathology & Clinical Pathology
800 S MAIN
Corona, CA 92882
  • Reassigned Medicare billing, California enrollment
  • 4 clinicians in this Medicare group

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

Areas of Expertise CMS Part B claims 16

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Pathology examination of tissue using a microscope, intermediate complexity 88305
A pathology examination of tissue with intermediate complexity involves studying a small sample of your body tissue under a microscope. This helps in identifying any abnormal cells or signs of disease. It's a detailed process requiring expert analysis to ensure accurate results.
805 services361 patients
Special stained specimen slides to examine tissue, each additional procedure 88341
Special stained specimen slides are used to analyze tissue in detail. In this process, extra procedures may be needed for a more thorough examination. These involve applying special stains to the tissue on slides, enhancing specific elements for closer study.
515 services86 patients
Special stained specimen slides to examine tissue including interpretation and report 88313
Special stained specimen slides are used to examine tissue samples. This involves applying special dyes to the tissue, which helps to highlight certain features under a microscope. The findings are then interpreted and a report is provided. This can aid in diagnosing various health conditions.
296 services137 patients
Special stained specimen slides to examine tissue, initial procedure 88342
This procedure involves the use of specially stained slides to examine tissue samples. The initial process involves obtaining a small tissue sample from your body. This sample is then placed on a slide and stained with special dyes to highlight different structures and elements. The stained slide is then examined under a microscope to help diagnose any potential health issues.
257 services193 patients
Preparation of tissue for examination by removing any calcium present 88311
This procedure involves treating tissue samples to remove any calcium, which can interfere with the examination. The tissue is soaked in a special solution that safely dissolves the calcium, leaving the tissue intact for accurate analysis. This helps in making precise diagnoses.
156 services149 patients
Cell examination of body fluid, smears 88104
Cell examination of body fluid, or smear, is a laboratory test where a sample of your body fluid is taken. It's then thinly spread on a glass slide and examined under a microscope to check for abnormalities. This can help diagnose various health conditions.
149 services88 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92882 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
$136.04 typical visit price
range $59.60 – $179.42
Typical copayment $34.01 (range $14.90 – $44.85)
Most-billed visit code 99204
Established Patient
$104.64 typical visit price
range $19.37 – $146.42
Typical copayment $26.16 (range $4.84 – $36.60)
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.

Student in an Organized Health Care Education/Training Program
800 S MAIN ST
CORONA, CA 92882
Dietitian, Registered
800 S MAIN ST
CORONA, CA 92882
Physician Assistant
800 S MAIN ST
CORONA, CA 92882
Anesthesiology (Pain Medicine)
800 S MAIN ST
CORONA, CA 92882
Anesthesiology
800 S MAIN ST
CORONA, CA 92882
Physician Assistant
800 S MAIN ST
CORONA, CA 92882
Nurse Practitioner (Family)
800 S MAIN ST
CORONA, CA 92882
Anesthesiology
800 S MAIN ST
CORONA, CA 92882

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 Stephan Grigorian's NPI number?

The NPI number for Stephan Grigorian is 1821129057. It was assigned to this individual provider in the NPPES registry on March 8, 2007.

Where is Stephan Grigorian located?

Stephan Grigorian practices at 800 S Main St, Corona, CA 92882. The listed phone number is (858) 877-0267.

What is Stephan Grigorian's specialty?

The primary specialty registered for this NPI is Pathology, specializing in Anatomic Pathology & Clinical Pathology, with taxonomy code 207ZP0102X.

Is Stephan Grigorian enrolled in Medicare?

Yes. Stephan Grigorian is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for Stephan Grigorian's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Stephan Grigorian reassigns Medicare benefits to Boris Shlopov MD Pathology Medical Corporation (Corona, CA). The 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 Stephan Grigorian'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 Stephan Grigorian was last updated on August 29, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years 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.