Dr. Brian Marcial O'Connor, MD
- Medicare services, 2021
- 13,194
- Part D claims, 2024
- 12
- Industry payments
- $14,211
- Affiliated sites
- 2
- Medical groups
- 2
- Practice address
- 1562 Opossumtown Pike, Frederick, MD 21702-4920
- Practice phone
- Call (240) 215-6310
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Frederick Health Medical Group - Frederick (1562 Opossumtown Pike)
Primary care practice · Frederick, Maryland
Find Dr. O'Connor'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. Brian Marcial O'Connor is a medical oncologist in Frederick, Maryland
Dr. O'Connor practices at Frederick Health Medical Group - Frederick (1562 Opossumtown Pike) in Frederick, Maryland.
Dr. O'Connor's NPI, 1174515050, was assigned on August 17, 2005. Dr. O'Connor holds Maryland license D31761.
- NPI
- 1174515050NPI Registry (opens in a new tab)
- NPI enumeration date
- August 17, 2005
- NPI status
- Active
- Practice phone
- (240) 215-6310
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 70
- 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. Brian Marcial O'Connor practices at 2 locations in Frederick, Maryland
Dr. O'Connor's primary practice is Frederick Health Medical Group - Frederick (1562 Opossumtown Pike), at 1562 Opossumtown Pike, Frederick, MD 21702-4920. The practice phone is (240) 215-6310. The NPI Registry lists Dr. O'Connor's practice address as 400 W 7th St, Frederick, MD 21701.
- Frederick Health Medical Group - Frederick (1562 Opossumtown Pike)Primary1562 Opossumtown Pike, Frederick, MD 21702-4920Phone(240) 215-6310
- NPI Registry address400 W 7th St, Frederick, MD 21701 · Frederick CountyPhone(301) 662-8477
Sources: NPPES NPI Registry (CMS); Dmand AI Affiliation Data; Doctors and Clinicians National Downloadable File (CMS); and Dmand AI Practice Data
Dr. Brian Marcial O'Connor is affiliated with 2 sites of care and 2 medical groups
Dr. O'Connor's primary practice is Frederick Health Medical Group - Frederick (1562 Opossumtown Pike) in Frederick, Maryland. The medical group on file is Frederick Health Medical Group. Dmand AI also links Dr. O'Connor to 1 more group practice or clinic and 1 medical group, each named with a free account.
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dmand AI tracks the EHR system at Dr. Brian Marcial O'Connor's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. O'Connor practices, 2 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Frederick Health Medical Group - Frederick (1562 Opossumtown Pike) | Available with a free account |
| +1 more site and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Brian Marcial O'Connor is one of 157 medical oncologists in Maryland
Medical oncology is Dr. O'Connor's primary specialty in the NPI Registry, under taxonomy code 207RX0202X. Dr. O'Connor is licensed in Maryland.
Specialties and state licenses
- Medical oncology, MarylandPrimary
Medical oncologists near Dr. O'Connor
Counts of medical oncologists 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. Brian Marcial O'Connor billed Medicare for 13,194 services in 2021
CMS data shows 13,194 Medicare services from Dr. O'Connor across 26 procedure codes in 2021. Medicare paid $170,993 for them. Every service was in an office.
Dr. O'Connor's Medicare services by type, 2020 to 2021
- 2020
- 2021
- Drugs given in the office
- 2020: 38,2222021: 11,88469%
- Tests and treatments
- 2020: 1,9942021: 84258%
- Office and hospital visits
- 2020: 9782021: 44355%
- Surgery
- 2020: 222021: 2514%
Dr. O'Connor compared with the Maryland median for medical oncologists, 2021
- Dr. O'Connor
- Maryland median
- Medicare services
- 13,194vs 42231.3 times
- Part D claims
- 12vs 11890% below
Medians across 124 medical oncologists in Maryland with Dmand AI profiles that report each measure.
Dr. O'Connor'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. O'Connor and other medical oncologists in Maryland.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Brian Marcial O'Connor's patients have a median age of 69
Across all payers, Dmand AI patient panel data puts Dr. O'Connor's median patient age at 69, with 67% women.
Dr. O'Connor's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 69
Patient panel by sex, all payers
- Women67%
- Men33%
Source: Dmand AI Patient Panel Data
Dr. Brian Marcial O'Connor wrote 12 Medicare Part D claims in 2024
In 2024, Dr. O'Connor wrote 12 Medicare Part D claims. 100% of them were for generic drugs. They cover 1 drug, with $293 in total drug cost. In 2023, CMS named 12 claims across 1 drug.
Dr. O'Connor's most prescribed drugs by claims, 2024
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, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 122024: 12No change
Drugs named by CMS: 1 in 2024, 1 in 2023.
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. Brian Marcial O'Connor received $14,211 in industry payments from 2016 to 2021
CMS Open Payments shows 221 general payments to Dr. O'Connor from 41 drug and device companies from 2016 to 2021. Consulting fees make up the largest share, 65% of the total. Alkermes, Inc. paid the most, $9,225.
General payments to Dr. O'Connor by program year, 2016 to 2021
General payments to Dr. O'Connor by kind, 2016 to 2021
- Consulting fees$9,22565%
- Food and beverage$4,10229%
- Travel and lodging$8646%
- Education$200%
Companies that paid Dr. O'Connor the most, 2016 to 2021
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Dr. Brian Marcial O'Connor'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Dmand AI Practice Data |
| 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)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| 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. Brian Marcial O'Connor
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What is Dr. Brian Marcial O'Connor's NPI number?
Dr. Brian Marcial O'Connor's NPI number is 1174515050. It was assigned on August 17, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. Brian Marcial O'Connor?
Dr. Brian Marcial O'Connor is a medical oncologist in Frederick, Maryland. The primary specialty in the NPI Registry is Medical Oncology Physician (taxonomy code 207RX0202X).
Where does Dr. Brian Marcial O'Connor practice?
Dr. O'Connor practices at 1562 Opossumtown Pike, Frederick, MD 21702-4920. Dr. O'Connor also practices at 400 W 7th St, Frederick, MD 21701. Dr. O'Connor's primary practice is Frederick Health Medical Group - Frederick (1562 Opossumtown Pike) in Frederick, Maryland. Dmand AI also links Dr. O'Connor to 1 group practice or clinic and 1 medical group.
What is Dr. Brian Marcial O'Connor's office phone number?
The practice phone on file for Dr. O'Connor is (240) 215-6310.
What is Dr. Brian Marcial O'Connor's medical license number?
Dr. O'Connor holds Maryland license D31761.
What medical group is Dr. Brian Marcial O'Connor part of?
Dr. O'Connor is linked to Frederick Health Medical Group. Dmand AI links Dr. O'Connor to 1 more medical group.
Does Dr. Brian Marcial O'Connor accept Medicare?
Yes. CMS data shows Dr. O'Connor billed Medicare for 13,194 services in 2021.
What services does Dr. Brian Marcial O'Connor bill to Medicare?
In 2021, Dr. O'Connor's most billed Medicare services were injected or infused drug (J0185), injected or infused drug (J0897) and injected or infused drug (J1100).
What drugs does Dr. Brian Marcial O'Connor prescribe most?
In 2024 Medicare Part D data, Dr. O'Connor's most prescribed drugs by claims were Methotrexate.
Has Dr. Brian Marcial O'Connor received payments from drug or device companies?
CMS Open Payments shows $14,211 in general payments to Dr. O'Connor from 41 companies from 2016 to 2021. The largest total came from Alkermes, Inc.
How long has Dr. Brian Marcial O'Connor been practicing?
Dr. O'Connor graduated from medical school in 1982, 44 years ago.
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