Dr. Gregory S. Sibley, MD
- Medicare services, 2024
- 14,547
- Medicare patients, 2024
- 272
- Part D claims, 2024
- 94
- Industry payments
- $8,396
- Affiliated sites
- 1
- Practice address
- 8613 Lee Hwy, Fairfax, VA 22031
- Practice phone
- Call (703) 280-5390
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Virginia Cancer Specialists
Fairfax, Virginia
Find Dr. Sibley'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. Gregory S. Sibley is a radiation oncologist in Fairfax, Virginia
Dr. Sibley practices at Virginia Cancer Specialists in Fairfax, Virginia.
Dr. Sibley's NPI, 1043211360, was assigned on August 9, 2005. Dr. Sibley graduated from University of Michigan Medical School in 1990. Dr. Sibley holds Virginia license 0101052359.
- NPI
- 1043211360NPI Registry (opens in a new tab)
- Medicare PAC ID
- 6103961784
- NPI enumeration date
- August 9, 2005
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
- Practice phone
- (703) 280-5390
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 62
- Medical school graduation
- 1990
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Gregory S. Sibley practices at Virginia Cancer Specialists in Fairfax, Virginia
Dr. Sibley's primary practice is Virginia Cancer Specialists, at 8613 Lee Hwy, Fairfax, VA 22031 in Fairfax County. The practice phone is (703) 280-5390.
- Virginia Cancer Specialists8613 Lee Hwy, Fairfax, VA 22031 · Fairfax CountyPhone(703) 280-5390
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Gregory S. Sibley is affiliated with 2 sites of care and 1 medical group
Dr. Sibley's primary practice is Virginia Cancer Specialists in Fairfax, Virginia. The medical group on file is Virginia Cancer Specialists. Dmand AI also links Dr. Sibley to 1 more group practice or clinic, named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Gregory S. Sibley's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Sibley practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Virginia Cancer Specialists | Available with a free account |
| +1 more affiliated site | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across each health system and 6.2K+ hospitals, with verified contacts in the same login.
Dr. Gregory S. Sibley is one of 139 radiation oncologists in Virginia
Radiation oncology is Dr. Sibley's primary specialty in the NPI Registry, under taxonomy code 2085R0001X. Dmand AI has Dr. Sibley's licenses on file in 3 states: Virginia, District of Columbia and Maryland.
Specialties and state licenses
- Radiation oncology, VirginiaPrimary
- Specialist, District of Columbia
- Maryland license
Radiation oncologists near Dr. Sibley
Counts of radiation 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. Gregory S. Sibley billed Medicare for 14,547 services in 2024
CMS data shows 14,547 Medicare services from Dr. Sibley across 30 procedure codes in 2024, for 272 Medicare patients. Medicare paid $2,260,305 for them. Every service was in an office.
Dr. Sibley's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Other services
- 2023: 11,1362024: 11,9237%
- Imaging
- 2023: 2,2252024: 2,2431%
- Office and hospital visits
- 2023: 3072024: 2925%
- Lab and pathology
- 2023: 1152024: 6246%
- Surgery
- 2023: 332024: 2718%
Dr. Sibley compared with the Virginia median for radiation oncologists, 2024
- Dr. Sibley
- Virginia median
- Medicare services
- 14,547vs 1,8387.9 times
- Medicare patients
- 272vs 2566% above
- Part D claims
- 56vs 4330% above
Medians across 138 radiation oncologists in Virginia with Dmand AI profiles that report each measure.
Dr. Sibley'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.
Need commercial claims for Dr. Sibley?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Sibley and other radiation oncologists in Virginia.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Gregory S. Sibley treated 272 Medicare patients in 2024, average age 76
CMS counts 272 Medicare patients who saw Dr. Sibley in 2024. The largest group is 65 to 74, with 125 patients. 75% of them have cancer, and 74% have high cholesterol. 5% are also on Medicaid. Their average risk score is 1.84, 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. Sibley's median patient age at 69, with 46% women.
Dr. Sibley's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Sibley's Medicare patients by sex, 2024
- Women12245%
- Men15055%
Chronic conditions among Dr. Sibley's Medicare patients, 2024
- Cancer75%
- High cholesterol74%
- High blood pressure72%
- Arthritis44%
- Ischemic heart disease28%
- Diabetes23%
- Atrial fibrillation21%
- Mood disorders19%
Share of Medicare patients with each condition. A patient can have several.
Dr. Sibley'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
- Women46%
- Men51%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Gregory S. Sibley wrote 94 Medicare Part D claims in 2024
In 2024, Dr. Sibley wrote 94 Medicare Part D claims for 42 patients. 78% of them were for generic drugs. CMS names the drug for 56 of them, across 3 drugs with 11 or more claims each, at $43,125 in total drug cost. In 2023, CMS named 52 claims across 2 drugs.
Dr. Sibley's Part D claims by kind of drug, 2024
- Generic73 claims78%
- Brand-name21 claims22%
Dr. Sibley'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.
Drug classes CMS tracks in Dr. Sibley's Part D claims, 2024
- Antibiotics18%17 of 94 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: 522024: 568%
Drugs named by CMS: 3 in 2024, 2 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
Dr. Gregory S. Sibley offers telehealth to Medicare patients
Dr. Sibley accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Sibley as offering telehealth.
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
For MedTech and pharma teams
Filter 7.4M+ HCPs by Medicare procedures, Part D drugs and Open Payments history, then reach them with verified contacts in one login.
Dr. Gregory S. Sibley received $8,396 in industry payments from 2016 to 2025
CMS Open Payments shows 23 general payments to Dr. Sibley from 11 drug and device companies from 2016 to 2025. Consulting fees make up the largest share, 72% of the total. Novartis Pharmaceuticals Corporation paid the most, $7,900.
General payments to Dr. Sibley by program year, 2016 to 2025
General payments to Dr. Sibley by kind, 2016 to 2025
- Consulting fees$6,05072%
- Travel and lodging$1,66120%
- Food and beverage$6858%
Companies that paid Dr. Sibley 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 S. Sibley graduated from University of Michigan Medical School
Dr. Sibley graduated from University of Michigan Medical School in 1990.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Gregory S. Sibley'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 |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand 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) |
| 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. Gregory S. Sibley
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 S. Sibley's NPI number?
Dr. Gregory S. Sibley's NPI number is 1043211360. It was assigned on August 9, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. Gregory S. Sibley?
Dr. Gregory S. Sibley is a radiation oncologist in Fairfax, Virginia. The primary specialty in the NPI Registry is Radiation Oncology Physician (taxonomy code 2085R0001X).
Where does Dr. Gregory S. Sibley practice?
Dr. Sibley practices at 8613 Lee Hwy, Fairfax, VA 22031. Dr. Sibley's primary practice is Virginia Cancer Specialists in Fairfax, Virginia. Dmand AI also links Dr. Sibley to 1 group practice or clinic.
What is Dr. Gregory S. Sibley's office phone number?
The practice phone on file for Dr. Sibley is (703) 280-5390.
What is Dr. Gregory S. Sibley's medical license number?
Dr. Sibley holds Virginia license 0101052359, one of the licenses on file in 3 states.
Which states has Dr. Gregory S. Sibley been licensed in?
Dmand AI has state licenses on file for Dr. Sibley in Virginia, District of Columbia and Maryland.
What medical group is Dr. Gregory S. Sibley part of?
Dr. Sibley is linked to Virginia Cancer Specialists.
Does Dr. Gregory S. Sibley accept Medicare?
Yes. CMS data shows Dr. Sibley billed Medicare for 14,547 services in 2024, and Dr. Sibley accepts Medicare assignment.
Does Dr. Gregory S. Sibley offer telehealth?
Yes. The CMS Doctors and Clinicians file lists Dr. Sibley as offering telehealth services.
How many Medicare patients does Dr. Gregory S. Sibley see?
CMS counts 272 Medicare patients who saw Dr. Sibley in 2024, with an average age of 76.
Show 5 more questionsShow fewer questions
What services does Dr. Gregory S. Sibley bill to Medicare?
In 2024, Dr. Sibley's most billed Medicare services were medical supplies or transport (A9607), medicare temporary code (Q9967) and medicare service (G6015).
Where did Dr. Gregory S. Sibley go to medical school?
Dr. Sibley graduated from University of Michigan Medical School in 1990.
What drugs does Dr. Gregory S. Sibley prescribe most?
In 2024 Medicare Part D data, Dr. Sibley's most prescribed drugs by claims were Tamsulosin HCl, Orgovyx and Ciprofloxacin HCl.
Has Dr. Gregory S. Sibley received payments from drug or device companies?
CMS Open Payments shows $8,396 in general payments to Dr. Sibley from 11 companies from 2016 to 2025. The largest total came from Novartis Pharmaceuticals Corporation.
How long has Dr. Gregory S. Sibley been practicing?
Dr. Sibley graduated from medical school in 1990, 36 years ago.
Selling to radiation oncology practices?
See radiation oncologists in Virginia by site of care and group
Find the practices, groups and hospitals they work with, and the right people to contact at each.
- 30 days free
- Self-serve
- No credit card