Dr. Dennis Obrien, MD
- Medicare services, 2021
- 36
- Part D claims, 2019
- 12
- Industry payments
- $37
- State license
- 1
- Year NPI issued
- 2005
- Practice address
- 801 N 29th St, Billings, MT 59101-0905
- Practice phone
- Call (406) 238-2500
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Find Dr. Obrien'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. Dennis Obrien is a neurologist in Billings, Montana
Dr. Obrien practices in Billings, Montana.
Dr. Obrien's NPI, 1811981699, was assigned on September 7, 2005. Dr. Obrien holds Illinois license 36099965.
- NPI
- 1811981699NPI Registry (opens in a new tab)
- NPI enumeration date
- September 7, 2005
- NPI status
- Active
- Practice phone
- (406) 238-2500
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
Sources: NPPES NPI Registry (CMS); and Dmand AI Professional Profile Data
Dr. Dennis Obrien's practice address is in Billings, Montana
Dr. Obrien's practice address in the NPI Registry is 801 N 29th St, Billings, MT 59101-0905. The practice phone is (406) 238-2500.
- NPI Registry address801 N 29th St, Billings, MT 59101-0905Phone(406) 238-2500
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dmand AI tracks the EHR system at Dr. Dennis Obrien's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Obrien practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Dr. Obrien's practice | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Dennis Obrien is one of 57 neurologists in Montana
Neurology is Dr. Obrien's primary specialty in the NPI Registry, under taxonomy code 2084N0400X. Dr. Obrien is licensed in Illinois.
Specialties and state licenses
- Neurology, IllinoisPrimary
Neurologists near Dr. Obrien
Counts of neurologists 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. Dennis Obrien billed Medicare for 36 services in 2021
CMS data shows 36 Medicare services from Dr. Obrien across 2 procedure codes in 2021. Medicare paid $6,212 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Obrien's Medicare services by type, 2020 to 2021
- 2020
- 2021
- Office and hospital visits
- 2020: 1182021: 3669%
Dr. Obrien compared with the Montana median for neurologists, 2021
- Dr. Obrien
- Montana median
- Medicare services
- 36vs 34990% below
- Part D claims
- 12vs 46497% below
Medians across 56 neurologists in Montana with Dmand AI profiles that report each measure.
Dr. Obrien'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. Obrien and other neurologists in Montana.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Dennis Obrien's patients have a median age of 64
Across all payers, Dmand AI patient panel data puts Dr. Obrien's median patient age at 64, with 71% women.
Dr. Obrien's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 64
Patient panel by sex, all payers
- Women71%
- Men29%
Source: Dmand AI Patient Panel Data
Dr. Dennis Obrien wrote 12 Medicare Part D claims in 2019
In 2019, Dr. Obrien wrote 12 Medicare Part D claims. Every claim was for a generic drug. They cover 1 drug, with $27,040 in total drug cost. In 2018, CMS named 13 claims across 1 drug.
Dr. Obrien's most prescribed drugs by claims, 2019
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, 2018 to 2019
- 2018
- 2019
- Claims for drugs CMS names
- 2018: 132019: 128%
Drugs named by CMS: 1 in 2019, 1 in 2018.
Source: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026
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Dr. Dennis Obrien received $37 in industry payments from 2021 to 2022
CMS Open Payments shows 2 general payments to Dr. Obrien from 1 drug or device company from 2021 to 2022. Food and beverage make up the largest share, 100% of the total. Novo Nordisk Inc paid the most, $37.
General payments to Dr. Obrien by program year, 2021 to 2022
Companies that paid Dr. Obrien the most, 2021 to 2022
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Dr. Dennis Obrien'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 Practice 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 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) |
| 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. Dennis Obrien
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. Dennis Obrien's NPI number?
Dr. Dennis Obrien's NPI number is 1811981699. It was assigned on September 7, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. Dennis Obrien?
Dr. Dennis Obrien is a neurologist in Billings, Montana. The primary specialty in the NPI Registry is Neurology Physician (taxonomy code 2084N0400X).
Where does Dr. Dennis Obrien practice?
Dr. Obrien practices at 801 N 29th St, Billings, MT 59101-0905.
What is Dr. Dennis Obrien's office phone number?
The practice phone on file for Dr. Obrien is (406) 238-2500.
What is Dr. Dennis Obrien's medical license number?
Dr. Obrien holds Illinois license 36099965.
Does Dr. Dennis Obrien accept Medicare?
Yes. CMS data shows Dr. Obrien billed Medicare for 36 services in 2021.
What services does Dr. Dennis Obrien bill to Medicare?
In 2021, Dr. Obrien's most billed Medicare services were critical care (99291) and hospital inpatient care (99223).
What drugs does Dr. Dennis Obrien prescribe most?
In 2019 Medicare Part D data, Dr. Obrien's most prescribed drugs by claims were Tetrabenazine.
Has Dr. Dennis Obrien received payments from drug or device companies?
CMS Open Payments shows $37 in general payments to Dr. Obrien from 1 company from 2021 to 2022. The largest total came from Novo Nordisk Inc.
How long has Dr. Dennis Obrien been practicing?
Dr. Obrien's NPI was assigned in 2005.
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