Dr. John Hollenberg, MD
- Medicare services, 2021
- 54
- Part D claims, 2021
- 927
- Industry payments
- $3,657
- Affiliated sites
- 1
- Medical group
- 1
- Practice address
- 7621 Canoga Ave, Canoga Park, CA 91304
- Practice phone
- Call (818) 598-6900
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave)
Behavioral health practice · Canoga Park, California
Find Dr. Hollenberg's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. John Hollenberg is a psychiatrist in California
Dr. Hollenberg practices at Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave) in Canoga Park, California.
Dr. Hollenberg's NPI, 1083799225, was assigned on October 26, 2006. Dr. Hollenberg graduated from Tulane School of Medicine in 1982. Dr. Hollenberg holds California license G00051020.
- NPI
- 1083799225NPI Registry (opens in a new tab)
- NPI enumeration date
- October 26, 2006
- NPI status
- Active
- Practice phone
- (818) 598-6900
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Medical school graduation
- 1982
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. John Hollenberg practices at Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave) in Canoga Park, California
Dr. Hollenberg's primary practice is Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave), at 7621 Canoga Ave, Canoga Park, CA 91304. The practice phone is (818) 598-6900.
- Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave)7621 Canoga Ave, Canoga Park, CA 91304Phone(818) 598-6900
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. John Hollenberg is affiliated with 1 site of care and 1 medical group
Dr. Hollenberg's primary practice is Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave) in Canoga Park, California. The medical group on file is GENESIS Older Adult Program (Los Angeles County Department of Mental Health).
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dmand AI tracks the EHR system at Dr. John Hollenberg's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Hollenberg practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave) | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. John Hollenberg is one of 6,803 psychiatrists in California
Psychiatry is Dr. Hollenberg's primary specialty in the NPI Registry, under taxonomy code 2084P0800X. Dr. Hollenberg is board certified in anatomic pathology & clinical pathology by the American Board of Pathology. Dr. Hollenberg is licensed in California.
Specialties and state licenses
- Psychiatry, CaliforniaPrimary
Psychiatrists near Dr. Hollenberg
Counts of psychiatrists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. John Hollenberg billed Medicare for 54 services in 2021
CMS data shows 54 Medicare services from Dr. Hollenberg across 1 procedure code in 2021. Medicare paid $4,856 for them. Every service was in an office.
Dr. Hollenberg's Medicare services by type, 2020 to 2021
- 2020
- 2021
- Office and hospital visits
- 2020: 522021: 544%
Dr. Hollenberg compared with the California median for psychiatrists, 2021
- Dr. Hollenberg
- California median
- Medicare services
- 54vs 11955% below
- Part D claims
- 927vs 1446.4 times
Medians across 6,809 psychiatrists in California with Dmand AI profiles that report each measure.
Dr. Hollenberg's most billed Medicare procedure codes, 2021
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Hollenberg and other psychiatrists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. John Hollenberg's patients have a median age of 53
Across all payers, Dmand AI patient panel data puts Dr. Hollenberg's median patient age at 53, with 29% women.
Dr. Hollenberg's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 53
Patient panel by sex, all payers
- Women29%
- Men71%
Source: Dmand AI Patient Panel Data
Dr. John Hollenberg wrote 927 Medicare Part D claims in 2021
In 2021, Dr. Hollenberg wrote 927 Medicare Part D claims. They cover 30 drugs, with $225,678 in total drug cost. In 2020, CMS named 2,885 claims across 45 drugs.
Dr. Hollenberg's most prescribed drugs by claims, 2021
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Part D claims for drugs CMS names, 2020 to 2021
- 2020
- 2021
- Claims for drugs CMS names
- 2020: 2,8852021: 92768%
Drugs named by CMS: 30 in 2021, 45 in 2020.
Source: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026
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Dr. John Hollenberg received $3,657 in industry payments from 2016 to 2019
CMS Open Payments shows 225 general payments to Dr. Hollenberg from 8 drug and device companies from 2016 to 2019. Food and beverage make up the largest share, 99% of the total. Janssen Pharmaceuticals, Inc paid the most, $951.
General payments to Dr. Hollenberg by program year, 2016 to 2019
General payments to Dr. Hollenberg by kind, 2016 to 2019
- Food and beverage$3,63299%
- Education$191%
- Gifts$60%
Companies that paid Dr. Hollenberg the most, 2016 to 2019
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. John Hollenberg graduated from Tulane School of Medicine
Dr. Hollenberg graduated from Tulane School of Medicine in 1982.
- Medical school
- Board certified in anatomic pathology & clinical pathology
- Board certified in psychiatry
Source: Dmand AI Professional Profile Data
Sources for Dr. John Hollenberg's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. John Hollenberg
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. John Hollenberg's NPI number?
Dr. John Hollenberg's NPI number is 1083799225. It was assigned on October 26, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. John Hollenberg?
Dr. John Hollenberg is a psychiatrist in California. The primary specialty in the NPI Registry is Psychiatry Physician (taxonomy code 2084P0800X).
Where does Dr. John Hollenberg practice?
Dr. Hollenberg practices at 7621 Canoga Ave, Canoga Park, CA 91304. Dr. Hollenberg's primary practice is Genesis Countywide Older Adult Program - Canoga Park (Canoga Ave) in Canoga Park, California.
What is Dr. John Hollenberg's office phone number?
The practice phone on file for Dr. Hollenberg is (818) 598-6900.
What is Dr. John Hollenberg's medical license number?
Dr. Hollenberg holds California license G00051020.
What medical group is Dr. John Hollenberg part of?
Dr. Hollenberg is linked to GENESIS Older Adult Program (Los Angeles County Department of Mental Health).
Does Dr. John Hollenberg accept Medicare?
Yes. CMS data shows Dr. Hollenberg billed Medicare for 54 services in 2021.
Is Dr. John Hollenberg board certified?
Yes. Dr. Hollenberg is board certified in anatomic pathology & clinical pathology by the American Board of Pathology.
What services does Dr. John Hollenberg bill to Medicare?
In 2021, Dr. Hollenberg's most billed Medicare services were care management and other visits (99443).
Where did Dr. John Hollenberg go to medical school?
Dr. Hollenberg graduated from Tulane School of Medicine in 1982.
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What drugs does Dr. John Hollenberg prescribe most?
In 2021 Medicare Part D data, Dr. Hollenberg's most prescribed drugs by claims were Escitalopram Oxalate, Sertraline HCl and Trazodone HCl.
Has Dr. John Hollenberg received payments from drug or device companies?
CMS Open Payments shows $3,657 in general payments to Dr. Hollenberg from 8 companies from 2016 to 2019. The largest total came from Janssen Pharmaceuticals, Inc.
How long has Dr. John Hollenberg been practicing?
Dr. Hollenberg graduated from medical school in 1982, 44 years ago.
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