Faculty, MedicalNeurologyPhysicians, Women
Dr. Lazar John Greenfield Jr., MD, PhD
NPI1841286994PAC ID4385613181
- Medicare services, 2024
- 220
- Medicare patients, 2024
- 161
- Part D claims, 2024
- 1,012
- Publications
- 16
- Hospital affiliations
- 2
- Practice address
- 263 Farmington Ave, Farmington, CT 06030
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD
Childrens Hospital outpatient department · Farmington, Connecticut
Find Dr. Greenfield's professional email, personal email and mobile number
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Dr. Lazar John Greenfield Jr. is a neurologist in Farmington, Connecticut
Dr. Greenfield practices at Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD in Farmington, Connecticut.
Dr. Greenfield's NPI, 1841286994, was assigned on September 23, 2005. Dr. Greenfield graduated from University of Virginia School of Medicine in 1989. Dr. Greenfield holds Connecticut license 055487.
NPI and contact details
- NPI
- 1841286994NPI Registry (opens in a new tab)
- Medicare PAC ID
- 4385613181
- NPI enumeration date
- September 23, 2005
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 63
- Medical school graduation
- 1989
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Lazar John Greenfield Jr. practices at Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD in Farmington, Connecticut
Dr. Greenfield's primary practice is Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD, at 263 Farmington Ave, Farmington, CT 06030.
- Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD263 Farmington Ave, Farmington, CT 06030
Source: Dmand AI Affiliation Data
Dr. Lazar John Greenfield Jr. is affiliated with 5 sites of care and 4 medical groups
Dr. Greenfield's primary practice is Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD in Farmington, Connecticut. Dr. Greenfield is also affiliated with UConn John Dempsey Hospital. The medical group on file is Hartford Hospital. Dmand AI also links Dr. Greenfield to 1 more hospital, 3 medical groups and 2 group practices and clinics, each named with a free account.
Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPDPrimary
Source: Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Lazar John Greenfield Jr.'s practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Greenfield practices, 5 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD | Available with a free account |
| +4 more sites and 3 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Lazar John Greenfield Jr. is one of 302 neurologists in Connecticut
Neurology is Dr. Greenfield's primary specialty in the NPI Registry, under taxonomy code 2084N0400X. Dmand AI has Dr. Greenfield's licenses on file in 3 states: Connecticut, Arkansas and Ohio.
Specialties and state licenses
- Neurology, ConnecticutPrimary
- Clinical neurophysiology, Arkansas
- Ohio license
Neurologists near Dr. Greenfield
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. Lazar John Greenfield Jr. billed Medicare for 220 services in 2024
CMS data shows 220 Medicare services from Dr. Greenfield across 7 procedure codes in 2024, for 161 Medicare patients. Medicare paid $17,238 for them.
Medicare services, 2024220
Medicare patients161
Paid by Medicare$17,238
Procedure codes7
Dr. Greenfield's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 1132024: 1057%
- Other services
- 2023: 02024: 62
- Tests and treatments
- 2023: 342024: 5356%
Where Dr. Greenfield's Medicare services took place, 2024
- In an office14968%
- In a facility7132%
Dr. Greenfield compared with the Connecticut median for neurologists, 2024
- Dr. Greenfield
- Connecticut median
- Medicare services
- 220vs 223Close to median
- Medicare patients
- 161vs 157Close to median
- Part D claims
- 890vs 2413.7 times
Medians across 293 neurologists in Connecticut with Dmand AI profiles that report each measure.
Dr. Greenfield'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. Greenfield and other neurologists in Connecticut.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Lazar John Greenfield Jr. treated 161 Medicare patients in 2024, average age 69
CMS counts 161 Medicare patients who saw Dr. Greenfield in 2024. The largest group is under 65, with 52 patients. 68% of them have high blood pressure, and 62% have high cholesterol. 47% are also on Medicaid. Their average risk score is 1.93, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Greenfield's median patient age at 64, with 56% women.
Medicare patients, 2024161
Average age69
Average risk score1.93
Also on Medicaid47%
Dr. Greenfield's Medicare patients by age, 2024
Dr. Greenfield's Medicare patients by sex, 2024
- Women9157%
- Men7043%
Chronic conditions among Dr. Greenfield's Medicare patients, 2024
- High blood pressure68%
- High cholesterol62%
- Anxiety45%
- Mood disorders45%
- Arthritis41%
- Depression39%
- Stroke or TIA27%
- Alzheimer's and dementia26%
Share of Medicare patients with each condition. A patient can have several.
Dr. Greenfield'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
- Women56%
- Men44%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Lazar John Greenfield Jr. wrote 1,012 Medicare Part D claims in 2024
In 2024, Dr. Greenfield wrote 1,012 Medicare Part D claims for 98 patients. 89% of them were for generic drugs. CMS names the drug for 890 of them, across 26 drugs with 11 or more claims each, at $122,129 in total drug cost. In 2023, CMS named 677 claims across 21 drugs.
Part D claims, 20241,012
Drugs named by CMS26
Total drug cost$122,129
Part D patients98
Dr. Greenfield's Part D claims by kind of drug, 2024
- Generic901 claims89%
- Brand-name86 claims8%
- Other25 claims2%
Dr. Greenfield'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: 6772024: 89031%
Drugs named by CMS: 26 in 2024, 21 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
How Dr. Lazar John Greenfield Jr. takes part in Medicare
Dr. Greenfield 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. Lazar John Greenfield Jr. has 16 publications on record
Dmand AI links 16 papers to Dr. Greenfield, published from 2011 to 2024. 2012 was the busiest year, with 2. The most frequent topics are Seizures, Interneurons and CA1 Region, Hippocampal. Dr. Greenfield has published most often in Epilepsy Res. Dr. Greenfield's most frequent co-authors are Deborah Y. Bradshaw, MD, Damien Eugene Earl, MD, PhD and Mohammad Phillip Charles Fejleh, MD.
Papers16
Years published2011 to 2024
Dr. Greenfield's papers by year, 2011 to 2024
Topics Dr. Greenfield writes about most
- Seizures
- Interneurons
- CA1 Region, Hippocampal
- Electroencephalography
- Hippocampus
- Mice, Inbred C57BL
- Brain
- Brain Waves
Dr. Greenfield's most frequent co-authors
- Deborah Y. Bradshaw, MD1 shared paper
- Damien Eugene Earl, MD, PhD1 shared paper
- Mohammad Phillip Charles Fejleh, MD1 shared paper
Recent publications by Dr. Greenfield
BrainBrain MappingElectrocorticography
CA1 Region, HippocampalCholecystokininDisease Models, Animal
Neuropharmacology
CA1 Region, HippocampalCalcium-Calmodulin-Dependent Protein Kinase Type 2Excitatory Amino Acid Antagonists
Brain WavesCalcium Channels, L-TypeHippocampus
See who Dr. Greenfield researches with
Physician Network Discovery turns co-authorship, shared hospitals and shared groups into a map of who Dr. Greenfield works with, so you can find a warm path to the right neurologists.
Sources: PubMed (National Library of Medicine); and Dmand AI Research Linkage
Dr. Lazar John Greenfield Jr. received $4,640 in industry payments from 2017 to 2023
CMS Open Payments shows 4 general payments to Dr. Greenfield from 4 drug and device companies from 2017 to 2023. Consulting fees make up the largest share, 97% of the total. PTC Therapeutics, Inc. paid the most, $4,500.
General payments to Dr. Greenfield by program year, 2017 to 2023
General payments to Dr. Greenfield by kind, 2017 to 2023
$4.6Kin total
- Consulting fees$4,50097%
- Food and beverage$1403%
Companies that paid Dr. Greenfield the most, 2017 to 2023
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Lazar John Greenfield Jr. graduated from University of Virginia School of Medicine
Dr. Greenfield graduated from University of Virginia School of Medicine in 1989.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Lazar John Greenfield Jr.'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 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) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Publications, topics and co-authors | PubMed (National Library of Medicine) (opens in a new tab)Dmand AI Research Linkage |
| 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. Lazar John Greenfield Jr.
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. Lazar John Greenfield Jr.'s NPI number?
Dr. Lazar John Greenfield Jr.'s NPI number is 1841286994. It was assigned on September 23, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. Lazar John Greenfield Jr.?
Dr. Lazar John Greenfield Jr. is a neurologist in Farmington, Connecticut. The primary specialty in the NPI Registry is Neurology Physician (taxonomy code 2084N0400X).
Where does Dr. Lazar John Greenfield Jr. practice?
Dr. Greenfield practices at 263 Farmington Ave, Farmington, CT 06030. Dr. Greenfield's primary practice is Uconn Health Carole and Ray Neag Comprehensive Cancer Center - HOPD in Farmington, Connecticut. Dmand AI also links Dr. Greenfield to 1 hospital, 3 medical groups and 2 group practices and clinics.
What is Dr. Lazar John Greenfield Jr.'s medical license number?
Dr. Greenfield holds Connecticut license 055487, one of the licenses on file in 3 states.
Which states has Dr. Lazar John Greenfield Jr. been licensed in?
Dmand AI has state licenses on file for Dr. Greenfield in Connecticut, Arkansas and Ohio.
Which hospitals is Dr. Lazar John Greenfield Jr. affiliated with?
Dr. Greenfield is affiliated with UConn John Dempsey Hospital. Dmand AI links Dr. Greenfield to 1 more hospital.
What medical group is Dr. Lazar John Greenfield Jr. part of?
Dr. Greenfield is linked to Hartford Hospital. Dmand AI links Dr. Greenfield to 3 more medical groups.
Does Dr. Lazar John Greenfield Jr. accept Medicare?
Yes. CMS data shows Dr. Greenfield billed Medicare for 220 services in 2024, and Dr. Greenfield accepts Medicare assignment.
How many Medicare patients does Dr. Lazar John Greenfield Jr. see?
CMS counts 161 Medicare patients who saw Dr. Greenfield in 2024, with an average age of 69.
What services does Dr. Lazar John Greenfield Jr. bill to Medicare?
In 2024, Dr. Greenfield's most billed Medicare services were medicare service (G2211), office visit, established patient (99214) and nerve and brain test (95720).
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Where did Dr. Lazar John Greenfield Jr. go to medical school?
Dr. Greenfield graduated from University of Virginia School of Medicine in 1989.
What drugs does Dr. Lazar John Greenfield Jr. prescribe most?
In 2024 Medicare Part D data, Dr. Greenfield's most prescribed drugs by claims were Levetiracetam, Oxcarbazepine and Gabapentin.
Has Dr. Lazar John Greenfield Jr. received payments from drug or device companies?
CMS Open Payments shows $4,640 in general payments to Dr. Greenfield from 4 companies from 2017 to 2023. The largest total came from PTC Therapeutics, Inc.
How long has Dr. Lazar John Greenfield Jr. been practicing?
Dr. Greenfield graduated from medical school in 1989, 37 years ago.
Does Dr. Lazar John Greenfield Jr. do research?
Dmand AI links 16 publications to Dr. Greenfield, published from 2011 to 2024.
Who does Dr. Lazar John Greenfield Jr. publish with?
Dr. Greenfield's most frequent co-authors are Deborah Y. Bradshaw, MD (1 shared paper), Damien Eugene Earl, MD, PhD (1 shared paper) and Mohammad Phillip Charles Fejleh, MD (1 shared paper).
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