Dr. Gregory J. Withers, MD
- Medicare services, 2024
- 256
- Medicare patients, 2024
- 155
- Part D claims, 2024
- 317
- Publications
- 1
- Hospital affiliations
- 1
- Practice address
- 301 W Huntington Dr, Arcadia, CA 91007
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Arcadia Family Medicine - HOPD
Acute Care Hospital outpatient department · Arcadia, California
Find Dr. Withers' 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. Gregory J. Withers is a neurosurgeon in Arcadia, California
Dr. Withers practices at Arcadia Family Medicine - HOPD in Arcadia, California.
Dr. Withers' NPI, 1700804382, was assigned on July 18, 2006. Dr. Withers graduated from David Geffen School of Medicine at UCLA in 1973. Dr. Withers holds California license G27800.
- NPI
- 1700804382NPI Registry (opens in a new tab)
- Medicare PAC ID
- 1951598903
- NPI enumeration date
- July 18, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 79
- Medical school graduation
- 1973
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Gregory J. Withers practices at Arcadia Family Medicine - HOPD in Arcadia, California
Dr. Withers' primary practice is Arcadia Family Medicine - HOPD, at 301 W Huntington Dr, Arcadia, CA 91007.
- Arcadia Family Medicine - HOPD301 W Huntington Dr, Arcadia, CA 91007
Source: Dmand AI Affiliation Data
Dr. Gregory J. Withers is affiliated with 4 sites of care and 1 medical group
Dr. Withers' primary practice is Arcadia Family Medicine - HOPD in Arcadia, California. Dr. Withers is also affiliated with USC Arcadia Hospital. The medical group on file is USC Care Medical Group. Dmand AI also links Dr. Withers to 1 more physician office and 1 group practice or clinic, each named with a free account.
Source: Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Gregory J. Withers' practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Withers practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Arcadia Family Medicine - HOPD | Available with a free account |
| +3 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Gregory J. Withers is one of 846 neurosurgeons in California
Neurological surgery is Dr. Withers' primary specialty in the NPI Registry, under taxonomy code 207T00000X. Dr. Withers is board certified in neurological surgery by the American Board of Neurological Surgery. Dr. Withers is licensed in California.
Specialties and state licenses
- Neurological surgery, CaliforniaPrimary
Clinical focus
Dmand AI lists back and neck pain treatment without fusion, craniotomy, lower back pain, neck pain and spine problems and spinal fusion among the conditions Dr. Withers treats.
Neurosurgeons near Dr. Withers
Counts of neurosurgeons 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. Gregory J. Withers billed Medicare for 256 services in 2024
CMS data shows 256 Medicare services from Dr. Withers across 6 procedure codes in 2024, for 155 Medicare patients. Medicare paid $24,053 for them.
Dr. Withers' Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 3972024: 25636%
Where Dr. Withers' Medicare services took place, 2024
- In an office17066%
- In a facility8634%
Dr. Withers compared with the California median for neurosurgeons, 2024
- Dr. Withers
- California median
- Medicare services
- 256vs 21619% above
- Medicare patients
- 155vs 154Close to median
- Part D claims
- 264vs 2610.2 times
Medians across 679 neurosurgeons in California with Dmand AI profiles that report each measure.
Dr. Withers' 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.
Need commercial claims for Dr. Withers?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Withers and other neurosurgeons in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Gregory J. Withers treated 155 Medicare patients in 2024, average age 77
CMS counts 155 Medicare patients who saw Dr. Withers in 2024. The largest group is 75 to 84, with 61 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 37% are also on Medicaid. Their average risk score is 2.14, 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. Withers' median patient age at 69, with 52% women.
Dr. Withers' Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Withers' Medicare patients by sex, 2024
- Women7649%
- Men7951%
Chronic conditions among Dr. Withers' Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis71%
- Diabetes56%
- Chronic kidney disease45%
- Ischemic heart disease39%
- Stroke or TIA38%
- Mood disorders37%
Share of Medicare patients with each condition. A patient can have several.
Dr. Withers' 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
- Women52%
- Men46%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Gregory J. Withers wrote 317 Medicare Part D claims in 2024
In 2024, Dr. Withers wrote 317 Medicare Part D claims for 65 patients. 100% of them were for generic drugs. CMS names the drug for 264 of them, across 6 drugs with 11 or more claims each, at $2,825 in total drug cost. In 2023, CMS named 298 claims across 6 drugs.
Dr. Withers' 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.
Drug classes CMS tracks in Dr. Withers' Part D claims, 2024
- Opioids5%15 of 317 claims
- Antibiotics5%15 of 317 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 2982024: 26411%
Drugs named by CMS: 6 in 2024, 6 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. Gregory J. Withers takes part in Medicare
Dr. Withers accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Laminectomy or laminotomy (partial removal of spine bones): 1 to 10 procedures (CMS shows small counts as a range)
Spinal fusion: 1 to 10 procedures (CMS shows small counts as a range)
Sources: Doctors and Clinicians National Downloadable File (CMS); and Doctors and Clinicians Utilization Data (CMS)
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Dr. Gregory J. Withers has 1 publication on record
Dmand AI links 1 paper to Dr. Withers in 2025.
Recent publications by Dr. Withers
See who Dr. Withers researches with
Physician Network Discovery turns co-authorship, shared hospitals and shared groups into a map of who Dr. Withers works with, so you can find a warm path to the right neurosurgeons.
Sources: PubMed (National Library of Medicine); and Dmand AI Research Linkage
Dr. Gregory J. Withers received $347 in industry payments from 2016 to 2025
CMS Open Payments shows 6 general payments to Dr. Withers from 5 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 97% of the total. Medtronic, Inc. paid the most, $164.
General payments to Dr. Withers by program year, 2016 to 2025
General payments to Dr. Withers by kind, 2016 to 2025
- Food and beverage$33897%
- Education$93%
Companies that paid Dr. Withers 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. Gregory J. Withers has 3 awards and honors on record
Dmand AI lists 3 awards for Dr. Withers, most recently AANS Fellow in 2012.
Awards and honors for Dr. Withers
- 2012
- AANS Fellow
- Undated
- ACS Fellow
- CMS Stage 1 EHR
Source: Dmand AI Professional Profile Data
Dr. Gregory J. Withers graduated from David Geffen School of Medicine at UCLA
Dr. Withers graduated from David Geffen School of Medicine at UCLA in 1973. Dr. Withers is a member of AANS and ACS.
- Medical school
- Board certified in neurological surgery
Source: Dmand AI Professional Profile Data
Dr. Gregory J. Withers accepts plans from 15 insurance carriers
Dr. Withers is in network with 15 carriers, including Aetna, Blue Cross Blue Shield of Michigan and United Healthcare. HMO plans come from the most carriers, 9. Check the plan with the practice before a visit.
- Aetna
- Blue Cross Blue Shield of Michigan
- United Healthcare
- HCSC
- LA Care
- Blue Cross Blue Shield of Massachusetts
- Elevance
- Molina
- +7 more carriersWith a free account
Plan types Dr. Withers accepts, by number of carriers
- HMO9
- Medicare9
- PPO7
- EPO4
- POS3
- Medicaid1
Source: Dmand AI Insurance Network Data
Sources for Dr. Gregory J. Withers'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)Doctors and Clinicians Utilization Data (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) |
| Awards and committee roles | Dmand AI Professional Profile Data |
| 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. Gregory J. Withers
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. Gregory J. Withers' NPI number?
Dr. Gregory J. Withers' NPI number is 1700804382. It was assigned on July 18, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Gregory J. Withers?
Dr. Gregory J. Withers is a neurosurgeon in Arcadia, California. The primary specialty in the NPI Registry is Neurological Surgery Physician (taxonomy code 207T00000X).
Where does Dr. Gregory J. Withers practice?
Dr. Withers practices at 301 W Huntington Dr, Arcadia, CA 91007. Dr. Withers' primary practice is Arcadia Family Medicine - HOPD in Arcadia, California. Dmand AI also links Dr. Withers to 1 physician office and 1 group practice or clinic.
What is Dr. Gregory J. Withers' medical license number?
Dr. Withers holds California license G27800.
Which hospitals is Dr. Gregory J. Withers affiliated with?
Dr. Withers is affiliated with USC Arcadia Hospital.
What medical group is Dr. Gregory J. Withers part of?
Dr. Withers is linked to USC Care Medical Group.
Does Dr. Gregory J. Withers accept Medicare?
Yes. CMS data shows Dr. Withers billed Medicare for 256 services in 2024, and Dr. Withers accepts Medicare assignment.
How many Medicare patients does Dr. Gregory J. Withers see?
CMS counts 155 Medicare patients who saw Dr. Withers in 2024, with an average age of 77.
Is Dr. Gregory J. Withers board certified?
Yes. Dr. Withers is board certified in neurological surgery by the American Board of Neurological Surgery.
What services does Dr. Gregory J. Withers bill to Medicare?
In 2024, Dr. Withers' most billed Medicare services were office visit, established patient (99213), hospital inpatient care (99222) and office visit, new patient (99204).
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Where did Dr. Gregory J. Withers go to medical school?
Dr. Withers graduated from David Geffen School of Medicine at UCLA in 1973.
What drugs does Dr. Gregory J. Withers prescribe most?
In 2024 Medicare Part D data, Dr. Withers' most prescribed drugs by claims were Meloxicam, Gabapentin and Levetiracetam.
Has Dr. Gregory J. Withers received payments from drug or device companies?
CMS Open Payments shows $347 in general payments to Dr. Withers from 5 companies from 2016 to 2025. The largest total came from Medtronic, Inc.
How long has Dr. Gregory J. Withers been practicing?
Dr. Withers graduated from medical school in 1973, 53 years ago.
Does Dr. Gregory J. Withers do research?
Dmand AI links 1 publication to Dr. Withers.
What insurance does Dr. Gregory J. Withers accept?
Dr. Withers is in network with 15 carriers, including Aetna, Blue Cross Blue Shield of Michigan and United Healthcare. HMO plans come from the most carriers, 9. Check the plan with the practice before a visit.
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