Dr. Glenn A. Marshak, MD
- Medicare services, 2024
- 762
- Medicare patients, 2024
- 27
- Part D claims, 2024
- 13
- Hospital affiliations
- 1
- Industry payments
- $609
- Practice address
- 1401 South Grand Avenue, Los Angeles, CA 90015
- Practice phone
- Call (213) 748-2411
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Find Dr. Marshak'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. Glenn A. Marshak is an internist in Los Angeles, California
Dr. Marshak practices at Dignity Health - California Hospital Medical Center in Los Angeles, California, part of CommonSpirit Health.
Dr. Marshak's NPI, 1104890029, was assigned on February 15, 2006. Dr. Marshak graduated from Chicago Medical School at Rosalind Franklin University of Medicine and Science in 1992. Dr. Marshak holds California license G78454.
- NPI
- 1104890029NPI Registry (opens in a new tab)
- NPI enumeration date
- February 15, 2006
- NPI status
- Active
- Practice phone
- (213) 748-2411
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 59
- Medical school graduation
- 1992
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Glenn A. Marshak practices at Dignity Health - California Hospital Medical Center in Los Angeles, California
Dr. Marshak's primary practice is Dignity Health - California Hospital Medical Center, at 1401 South Grand Avenue, Los Angeles, CA 90015 in Los Angeles County. The practice phone is (213) 748-2411.
- Dignity Health - California Hospital Medical Center1401 South Grand Avenue, Los Angeles, CA 90015 · Los Angeles CountyPhone(213) 748-2411
Source: Dmand AI Affiliation Data
Dr. Glenn A. Marshak is affiliated with 4 sites of care and 3 medical groups
Dr. Marshak's primary practice is Dignity Health - California Hospital Medical Center in Los Angeles, California, part of CommonSpirit Health. The medical group on file is Innovative Medical Solutions (IMS Med Group). Dmand AI also links Dr. Marshak to 2 more physician offices, 2 medical groups and 1 group practice or clinic, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Glenn A. Marshak's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Marshak practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Dignity Health - California Hospital Medical Center | Available with a free account |
| +3 more sites and 2 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Glenn A. Marshak is one of 16,751 internists in California
Internal medicine is Dr. Marshak's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Marshak is board certified in internal medicine by the American Board of Internal Medicine. Dr. Marshak is licensed in California.
Specialties and state licenses
- Internal medicine, CaliforniaPrimary
Internists near Dr. Marshak
Counts of internists 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. Glenn A. Marshak billed Medicare for 762 services in 2024
CMS data shows 762 Medicare services from Dr. Marshak across 2 procedure codes in 2024, for 27 Medicare patients. Medicare paid $15,664 for them. Every service was in an office.
Dr. Marshak's Medicare services by type, 2019 to 2024
- 2019
- 2024
- Drugs given in the office
- 2019: 02024: 720
- Tests and treatments
- 2019: 02024: 42
- Office and hospital visits
- 2019: 132024: 0100%
Dr. Marshak compared with the California median for internists, 2024
- Dr. Marshak
- California median
- Medicare services
- 762vs 3612.1 times
- Medicare patients
- 27vs 15182% below
- Part D claims
- 85vs 42180% below
Medians across 15,815 internists in California with Dmand AI profiles that report each measure.
Dr. Marshak's most billed Medicare procedure codes, 2024
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. Marshak and other internists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Glenn A. Marshak treated 27 Medicare patients in 2024, average age 75
CMS counts 27 Medicare patients who saw Dr. Marshak in 2024. The largest group is 75 to 84, with 13 patients. 75% of them have high blood pressure, and 75% have high cholesterol. Their average risk score is 1.19, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Marshak's median patient age at 52, with 48% women.
Dr. Marshak's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Chronic conditions among Dr. Marshak's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis67%
- Osteoporosis59%
- Ischemic heart disease48%
Share of Medicare patients with each condition. A patient can have several.
Dr. Marshak's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 52
Patient panel by sex, all payers
- Women48%
- Men52%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Glenn A. Marshak wrote 13 Medicare Part D claims in 2024
In 2024, Dr. Marshak wrote 13 Medicare Part D claims. 100% of them were for generic drugs. They cover 4 drugs, with $1,370 in total drug cost. In 2022, CMS named 114 claims across 5 drugs.
Dr. Marshak's most prescribed drugs by claims, 2023
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, 2022 to 2023
- 2022
- 2023
- Claims for drugs CMS names
- 2022: 1142023: 8525%
Drugs named by CMS: 4 in 2023, 5 in 2022.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Dr. Glenn A. Marshak received $609 in industry payments from 2016 to 2025
CMS Open Payments shows 11 general payments to Dr. Marshak from 10 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 100% of the total. Takeda Pharmaceuticals U.S.A., Inc. paid the most, $129.
General payments to Dr. Marshak by program year, 2016 to 2025
Companies that paid Dr. Marshak the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Glenn A. Marshak graduated from Chicago Medical School at Rosalind Franklin University of Medicine and Science
Dr. Marshak graduated from Chicago Medical School at Rosalind Franklin University of Medicine and Science in 1992.
- Medical school
- Board certified in internal medicine
Source: Dmand AI Professional Profile Data
Dr. Glenn A. Marshak accepts plans from 7 insurance carriers
Dr. Marshak is in network with 7 carriers, including Elevance, Blue Cross Blue Shield of Michigan and Blue Cross Blue Shield of Massachusetts. Medicare plans come from the most carriers, 7. Check the plan with the practice before a visit.
- Elevance
- Blue Cross Blue Shield of Michigan
- Blue Cross Blue Shield of Massachusetts
- HCSC
- Molina
- Regence Health Plans
- CMS Medicare
Plan types Dr. Marshak accepts, by number of carriers
- Medicare7
- PPO5
- HMO3
- POS2
- EPO1
Source: Dmand AI Insurance Network Data
Sources for Dr. Glenn A. Marshak'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 Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| 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 DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (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 |
| Insurance carriers and plan types | Dmand AI Insurance Network 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. Glenn A. Marshak
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. Glenn A. Marshak's NPI number?
Dr. Glenn A. Marshak's NPI number is 1104890029. It was assigned on February 15, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Glenn A. Marshak?
Dr. Glenn A. Marshak is an internist in Los Angeles, California. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Glenn A. Marshak practice?
Dr. Marshak practices at 1401 South Grand Avenue, Los Angeles, CA 90015. Dr. Marshak's primary practice is Dignity Health - California Hospital Medical Center in Los Angeles, California, part of CommonSpirit Health. Dmand AI also links Dr. Marshak to 2 physician offices, 2 medical groups and 1 group practice or clinic.
What is Dr. Glenn A. Marshak's office phone number?
The practice phone on file for Dr. Marshak is (213) 748-2411.
What is Dr. Glenn A. Marshak's medical license number?
Dr. Marshak holds California license G78454.
Which hospitals is Dr. Glenn A. Marshak affiliated with?
Dr. Marshak practices at Dignity Health - California Hospital Medical Center in Los Angeles, California.
What medical group is Dr. Glenn A. Marshak part of?
Dr. Marshak is linked to Innovative Medical Solutions (IMS Med Group). Dmand AI links Dr. Marshak to 2 more medical groups.
Does Dr. Glenn A. Marshak accept Medicare?
Yes. CMS data shows Dr. Marshak billed Medicare for 762 services in 2024.
How many Medicare patients does Dr. Glenn A. Marshak see?
CMS counts 27 Medicare patients who saw Dr. Marshak in 2024, with an average age of 75.
Is Dr. Glenn A. Marshak board certified?
Yes. Dr. Marshak is board certified in internal medicine by the American Board of Internal Medicine.
Show 6 more questionsShow fewer questions
What services does Dr. Glenn A. Marshak bill to Medicare?
In 2024, Dr. Marshak's most billed Medicare services were injected or infused drug (J0897) and infusion or chemotherapy administration (96372).
Where did Dr. Glenn A. Marshak go to medical school?
Dr. Marshak graduated from Chicago Medical School at Rosalind Franklin University of Medicine and Science in 1992.
What drugs does Dr. Glenn A. Marshak prescribe most?
In 2023 Medicare Part D data, Dr. Marshak's most prescribed drugs by claims were Metformin HCl, Atorvastatin Calcium and Tamsulosin HCl.
Has Dr. Glenn A. Marshak received payments from drug or device companies?
CMS Open Payments shows $609 in general payments to Dr. Marshak from 10 companies from 2016 to 2025. The largest total came from Takeda Pharmaceuticals U.S.A., Inc.
How long has Dr. Glenn A. Marshak been practicing?
Dr. Marshak graduated from medical school in 1992, 34 years ago.
What insurance does Dr. Glenn A. Marshak accept?
Dr. Marshak is in network with 7 carriers, including Elevance, Blue Cross Blue Shield of Michigan and Blue Cross Blue Shield of Massachusetts. Medicare plans come from the most carriers, 7. Check the plan with the practice before a visit.
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