MARK HREISH
NPI 1164839502
Psychiatry & Neurology - Psychiatry in Riverside, CA
About Mark Hreish NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARK HREISH (NPI 1164839502) is an individual psychiatry provider in Riverside, California, licensed in California (A137381) and active in the NPI registry since July 2014. He is enrolled in Medicare PECOS and is a graduate of Other (2012).
NPPES Registry Identity
Specialties & Licenses
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
Mark Hreish 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.
Medicare Billing Reassignment
Medicare enrollment records show Mark Hreish reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Riverside, CA 92505
- Reassigned Medicare billing, California enrollment
- 5,228 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 92505 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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.
RIVERSIDE, CA 92505
RIVERSIDE, CA 92505
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 Mark Hreish's NPI number?
The NPI number for Mark Hreish is 1164839502. It was assigned to this individual provider in the NPPES registry on July 17, 2014.
Where is Mark Hreish located?
Mark Hreish practices at 10800 Magnolia Ave, Riverside, CA 92505. The listed phone number is (951) 353-2000.
What is Mark Hreish's specialty?
The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.
Is Mark Hreish enrolled in Medicare?
Yes. Mark Hreish 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 Mark Hreish's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mark Hreish reassigns Medicare benefits to Southern California Permanente Medical Group (Riverside, 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 Mark Hreish'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 Mark Hreish was last updated on December 1, 2021. 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.
# Mark Hreish · NPI 1164839502
Psychiatry physician in Riverside, California. Individual provider, active in the CMS NPPES registry since July 17, 2014.
## Identity
- **NPI:** 1164839502 (Entity type: Individual)
- **Enumerated:** July 17, 2014
- **Primary specialty:** Psychiatry & Neurology - Psychiatry · taxonomy 2084P0800X
- **State license:** A137381 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 10800 MAGNOLIA AVE, Riverside, CA 92505-3043
- **Phone:** (951) 353-2000
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** Southern California Permanente Medical Group (NPI 1316979834, Riverside, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2012
## Record status
- **NPPES last updated:** December 1, 2021
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Source: [NPI Profile](https://npiprofile.com/npi/1164839502) · Data from the CMS NPPES public registry.