Dr. Daniel J. O'Brien, MD
- Medicare services, 2024
- 202
- Medicare patients, 2024
- 207
- Industry payments
- $92
- Affiliated sites
- 2
- Medical groups
- 4
- Practice address
- 300 Grove Street, Worcester, MA 01605
- Practice phone
- Call (508) 754-0700
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Worcester Surgical Center
Surgery Center - Medicare-Certified · Worcester, Massachusetts
Find Dr. O'Brien'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. Daniel J. O'Brien is an anesthesiologist in Worcester, Massachusetts
Dr. O'Brien practices at Worcester Surgical Center in Worcester, Massachusetts.
Dr. O'Brien's NPI, 1033144852, was assigned on July 11, 2006. Dr. O'Brien holds Massachusetts license 58686.
- NPI
- 1033144852NPI Registry (opens in a new tab)
- Medicare PAC ID
- 6002801016
- NPI enumeration date
- July 11, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (508) 754-0700
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 77
- Medical school graduation
- 1975
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Daniel J. O'Brien practices at Worcester Surgical Center in Worcester, Massachusetts
Dr. O'Brien's primary practice is Worcester Surgical Center, at 300 Grove Street, Worcester, MA 01605. The practice phone is (508) 754-0700.
- Worcester Surgical Center300 Grove Street, Worcester, MA 01605Phone(508) 754-0700
Source: Dmand AI Affiliation Data
Dr. Daniel J. O'Brien is affiliated with 2 sites of care and 4 medical groups
Dr. O'Brien's primary practice is Worcester Surgical Center in Worcester, Massachusetts. The medical group on file is Lahey Clinic. Dmand AI also links Dr. O'Brien to 3 more medical groups and 1 physician office, 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. Daniel J. O'Brien's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. O'Brien practices, 2 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Worcester Surgical Center | Available with a free account |
| +1 more site and 3 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Daniel J. O'Brien is one of 1,552 anesthesiologists in Massachusetts
Anesthesiology is Dr. O'Brien's primary specialty in the NPI Registry, under taxonomy code 207L00000X. Dr. O'Brien is licensed in Massachusetts.
Specialties and state licenses
- Anesthesiology, MassachusettsPrimary
Anesthesiologists near Dr. O'Brien
Counts of anesthesiologists 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. Daniel J. O'Brien billed Medicare for 202 services in 2024
CMS data shows 202 Medicare services from Dr. O'Brien across 5 procedure codes in 2024, for 207 Medicare patients. Medicare paid $20,668 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. O'Brien's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Anesthesia
- 2023: 1722024: 20217%
Dr. O'Brien compared with the Massachusetts median for anesthesiologists, 2024
- Dr. O'Brien
- Massachusetts median
- Medicare services
- 202vs 12660% above
- Medicare patients
- 207vs 200Close to median
Medians across 1,366 anesthesiologists in Massachusetts with Dmand AI profiles that report each measure.
Dr. O'Brien'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. O'Brien and other anesthesiologists in Massachusetts.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Daniel J. O'Brien treated 207 Medicare patients in 2024, average age 74
CMS counts 207 Medicare patients who saw Dr. O'Brien in 2024. The largest group is 65 to 74, with 100 patients. 75% of them have high cholesterol, and 71% have high blood pressure. 14% are also on Medicaid. Their average risk score is 1.02, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. O'Brien's median patient age at 58, with 56% women.
Dr. O'Brien's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. O'Brien's Medicare patients by sex, 2024
- Women13063%
- Men7737%
Chronic conditions among Dr. O'Brien's Medicare patients, 2024
- High cholesterol75%
- High blood pressure71%
- Arthritis43%
- Diabetes26%
- Anxiety23%
- Ischemic heart disease22%
- Mood disorders22%
- Depression20%
Share of Medicare patients with each condition. A patient can have several.
Dr. O'Brien's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 58
Patient panel by sex, all payers
- Women56%
- Men43%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
How Dr. Daniel J. O'Brien takes part in Medicare
Dr. O'Brien accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Daniel J. O'Brien received $92 in industry payments from 2017 to 2025
CMS Open Payments shows 3 general payments to Dr. O'Brien from 3 drug and device companies from 2017 to 2025. Food and beverage make up the largest share, 100% of the total. Edwards Lifesciences Corporation paid the most, $41.
General payments to Dr. O'Brien by program year, 2017 to 2025
Companies that paid Dr. O'Brien the most, 2017 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Dr. Daniel J. O'Brien'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) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (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. Daniel J. O'Brien
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. Daniel J. O'Brien's NPI number?
Dr. Daniel J. O'Brien's NPI number is 1033144852. It was assigned on July 11, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Daniel J. O'Brien?
Dr. Daniel J. O'Brien is an anesthesiologist in Worcester, Massachusetts. The primary specialty in the NPI Registry is Anesthesiology Physician (taxonomy code 207L00000X).
Where does Dr. Daniel J. O'Brien practice?
Dr. O'Brien practices at 300 Grove Street, Worcester, MA 01605. Dr. O'Brien's primary practice is Worcester Surgical Center in Worcester, Massachusetts. Dmand AI also links Dr. O'Brien to 3 medical groups and 1 physician office.
What is Dr. Daniel J. O'Brien's office phone number?
The practice phone on file for Dr. O'Brien is (508) 754-0700.
What is Dr. Daniel J. O'Brien's medical license number?
Dr. O'Brien holds Massachusetts license 58686.
What medical group is Dr. Daniel J. O'Brien part of?
Dr. O'Brien is linked to Lahey Clinic. Dmand AI links Dr. O'Brien to 3 more medical groups.
Does Dr. Daniel J. O'Brien accept Medicare?
Yes. CMS data shows Dr. O'Brien billed Medicare for 202 services in 2024, and Dr. O'Brien accepts Medicare assignment.
How many Medicare patients does Dr. Daniel J. O'Brien see?
CMS counts 207 Medicare patients who saw Dr. O'Brien in 2024, with an average age of 74.
What services does Dr. Daniel J. O'Brien bill to Medicare?
In 2024, Dr. O'Brien's most billed Medicare services were anesthesia (00142), anesthesia (00812) and anesthesia (00731).
Has Dr. Daniel J. O'Brien received payments from drug or device companies?
CMS Open Payments shows $92 in general payments to Dr. O'Brien from 3 companies from 2017 to 2025. The largest total came from Edwards Lifesciences Corporation.
How long has Dr. Daniel J. O'Brien been practicing?
Dr. O'Brien graduated from medical school in 1975, 51 years ago.
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