DR. GREGORY S SIBLEY M.D.
NPI 1043211360
Radiology - Radiation Oncology in Fairfax, VA

Q: What is Gregory Sibley's NPI number?

The NPI number for Gregory Sibley is 1043211360. It was assigned to this individual provider in the NPPES registry on August 9, 2005.

Q: What is Gregory Sibley's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Radiation Oncology, with taxonomy code 2085R0001X.

Q: When was this NPI record last updated?

The NPPES record for Gregory Sibley was last updated on November 11, 2025. NPI Profile syncs with the weekly NPPES data releases published by CMS.

Active since August 09, 2005PECOS EnrolledAccepts Medicare Assignment

91.96/100

CMS Quality Rating

8613 ROUTE 29 STE 100N, FAIRFAX, VA 22031(571) 350-8400(703) 280-9596 Get Directions Write a Review

NPPES record last updated: November 11, 2025. Verified against the NPPES registry weekly; last sync: July 26, 2026.

Record update history: Nov 11, 2025, Oct 26, 2022 (2 updates tracked since 2022).

On this page

About Dr. Gregory S Sibley M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. GREGORY S SIBLEY M.D. (NPI 1043211360) is an individual radiation oncology provider in Fairfax, Virginia, licensed in Virginia (0101052359) and active in the NPI registry since August 2005. He is enrolled in Medicare PECOS, is affiliated with Inova Alexandria Hospital, and is a graduate of University Of Michigan Medical School (1990).

NPPES Registry Identity

NPI1043211360

Entity TypeIndividualMale

Primary Taxonomy2085R0001X

Provider Legal NameDR. GREGORY S SIBLEYCredential: M.D.

Location Address8613 ROUTE 29 STE 100NFairfax, VA 22031-2172

Mailing Address3040 Williams Dr Ste 100Fairfax, VA 22031-4618 · (571) 350-8400 · Fax (703) 280-9596

Phone(571) 350-8400

Fax(703) 280-9596

Sole ProprietorNo

Medical School CMSUniversity Of Michigan Medical SchoolGraduated 1990

Enumeration DateAugust 9, 2005

Last NPPES UpdateNovember 11, 20252 updates tracked since enumeration

NPPES CertifiedNovember 11, 2025

✔ NPI 1043211360 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyRadiology · Radiation OncologyAllopathic & Osteopathic Physicians

Taxonomy Code2085R0001X

License✔ Licensed in VA · 0101052359

Definition

A radiologist who deals with the therapeutic applications of radiant energy and its modifiers and the study and management of disease, especially malignant tumors.

8613 ROUTE 29 STE 100N, Fairfax, VA 22031

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Other Identifiers 1

Medicaid5821738DC

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Gregory S Sibley M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6103961784

PECOS Enrollment IDI20100308000136, I20130911000013

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 30

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Lutetium lu 177 vipivotide tetraxetan, therapeutic, 1 millicurie A9607

Lutetium Lu 177 Vipivotide Tetraxetan is a type of radioactive drug treatment. It targets specific cells in the body, particularly those causing certain types of cancer. The drug attaches to these cells and emits radiation, destroying them. This helps control the growth and spread of the disease.

7,000 services16 patients

Low osmolar contrast material, 300-399 mg/ml iodine concentration, per ml Q9967

Low osmolar contrast material with 300-399 mg/ml iodine concentration is a diagnostic tool used in imaging procedures. It helps to enhance the visibility of specific areas in the body, aiding in accurate diagnosis. It's safe and generally well-tolerated by patients.

4,000 services37 patients

Intensity modulated treatment delivery, single or multiple fields/arcs,via narrow spatially and temporally modulated beams, binary, dynamic mlc, per treatment session G6015

Intensity-modulated radiation therapy (IMRT) is a type of cancer treatment. It uses advanced technology to manipulate photon beams of radiation to conform to the shape of a tumor. IMRT allows for the radiation dose to conform more precisely to the three-dimensional shape of the tumor by modulatingâ€”or controllingâ€”the intensity of the radiation beam. This can result in better tumor control and less harm to healthy tissue.

570 services68 patients

Ct guidance for insertion of radiation therapy fields 77014

CT guidance for insertion of radiation therapy fields involves using a CT scan to accurately map the area of your body where radiation will be applied. This ensures the radiation targets only the necessary area, minimizing impact to healthy tissues.

458 services66 patients

Calculation of radiation therapy dose 77300

Radiation therapy dose calculation is a process to determine the exact amount of radiation needed to treat a specific area in the body. This calculation helps ensure the treatment is effective while minimizing harm to healthy tissues. It's a key part of planning your radiation therapy.

394 services133 patients

Design and construction of complex radiation treatment device 77334

The design and construction of a complex radiation treatment device is a process where a specialized instrument is created. This device targets harmful cells with high-energy rays to destroy or damage them, while minimizing impact on healthy cells. This aids in treating conditions like cancer.

259 services92 patients

Continuing radiation therapy consultation per week 77336

Continuing radiation therapy consultation per week involves regular meetings with your healthcare team. These sessions help monitor your progress, manage side effects, and adjust your treatment plan if necessary. It's a key part of ensuring the effectiveness of your radiation therapy.

216 services124 patients

Radiation treatment delivery,3 or more separate treatment areas, custom blocking, tangential ports, wedges, rotational beam, compensators, electron beam; 6-10 mev G6012

Radiation therapy involves directing high-energy particles to destroy cancer cells. The technique targets 3 or more areas, using custom blocks for precise focus. Tangential ports, wedges, and rotational beams adjust the radiation's path, while compensators balance radiation dose. Electron beam therapy with 6-10 mev energy is used for deep-seated tumors.

181 services24 patients

Radiation treatment management, 5 treatment sessions 77427

Radiation treatment management involves a series of 5 sessions where targeted radiation is used to destroy or shrink cancer cells in your body. Each session is carefully planned to maximize effectiveness while minimizing harm to healthy tissues. You may experience side effects which will be closely monitored and managed for your comfort.

178 services92 patients

Radiation treatment delivery,3 or more separate treatment areas, custom blocking, tangential ports, wedges, rotational beam, compensators, electron beam; 11-19 mev G6013

This procedure involves using high-energy radiation to target and treat disease. It covers 3 or more distinct areas, using custom blocks to protect healthy tissue. Tangential ports, wedges, and rotational beams help direct the radiation. An electron beam of 11-19 million electron volts (mev) is used for deep-seated conditions.

172 services34 patients

Complex radiation therapy planning 77263

Complex radiation therapy planning is a process to determine the most effective way to deliver radiation to a specific area in your body. It involves detailed imaging to map your body's structure, allowing for precise targeting of cancer cells while sparing healthy tissue.

129 services121 patients

Cranial lesion surgery using radiation over multiple sessions 77373

Cranial lesion surgery using radiation involves targeting abnormal tissue in the brain with high-energy rays. This non-invasive procedure is done over multiple sessions to gradually destroy the lesion without harming healthy tissue. It's a precise, painless process often used when traditional surgery isn't possible.

128 services38 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

120 services120 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

96 services69 patients

Obtaining data needed to develop the optimal radiation treatment, 3 or more treatment areas or any number of treatment areas where special treatment is involved 77290

This procedure involves collecting necessary data to plan the best radiation treatment. It may cover 3 or more areas or any area requiring special attention. Data collection includes imaging scans and tests to understand the disease's extent and to tailor a precise, effective treatment plan.

77 services71 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

76 services60 patients

3d radiation therapy planning 77295

3D radiation therapy planning is a procedure that uses computer imaging to map out the area needing treatment. This ensures the radiation targets the disease precisely, while minimizing exposure to surrounding healthy tissues. It's a key step in preparing for effective radiation therapy.

73 services71 patients

Design and construction of radiation treatment device for high precision radiation therapy 77338

A radiation treatment device is custom-made for each patient to target cancer cells with high precision. It's designed to focus radiation on the tumor, sparing healthy tissue. This process ensures effective therapy while minimizing side effects.

71 services60 patients

High precision radiation therapy planning 77301

High precision radiation therapy planning involves detailed mapping of your body to target cancer cells accurately. Advanced imaging techniques help identify the exact location of the tumor, minimizing harm to healthy tissues. This personalized approach enhances effectiveness and reduces side effects.

61 services58 patients

Obtaining data needed to develop the optimal radiation treatment, 1 treatment area 77280

This procedure involves gathering essential information to create the best radiation treatment plan for a specific area. It includes scanning the treatment area and using this data to calculate the precise dose of radiation needed to target the disease effectively, while sparing healthy tissue.

43 services37 patients

Psa (prostate specific antigen) measurement, total 84153

PSA measurement is a simple blood test that checks for a specific protein produced by your body. High levels could indicate a health issue that needs further investigation. It's often used to monitor general wellness and is part of routine health screening.

42 services29 patients

X-ray during radiation therapy 77417

An X-ray during radiation therapy is a medical process that helps in tracking the progress of your treatment. It uses small amounts of radiation to create images of your body's internal structure. This aids in ensuring the therapy is accurately targeting the problem area and not harming healthy tissues.

40 services24 patients

Radioactive drug therapy through a vein 79101

Radioactive drug therapy through a vein involves injecting a drug with radioactive properties into your bloodstream. This drug travels throughout your body, targeting and destroying harmful cells, such as cancer cells, while sparing healthy ones. It's a non-invasive procedure to treat certain diseases.

34 services16 patients

Management of cranial lesion surgery using radiation over multiple sessions 77435

This procedure involves using targeted radiation to treat a lesion in the brain over several sessions. The radiation destroys the abnormal cells, helping to control or eliminate the lesion. It's a non-invasive treatment, meaning no surgical cuts are made.

28 services27 patients

Special medical radiation therapy consultation 77370

A special medical radiation therapy consultation involves discussing the use of high-energy radiation to treat diseases, primarily cancer. It's a chance to understand the process, potential side effects, and benefits. It is a key step in planning your treatment.

21 services21 patients

Blood test, comprehensive group of blood chemicals 80053

A comprehensive group of blood chemicals test, also known as a comprehensive metabolic panel, is a blood test that measures your sugar level, electrolyte and fluid balance, kidney function, and liver function. This helps to check your body's overall health.

20 services13 patients

Obtaining respiratory data needed to develop the optimal radiation treatment 77293

Obtaining respiratory data is vital for optimal radiation treatment. This involves tracking your breathing patterns to ensure the precise delivery of radiation to the target area, minimizing damage to healthy tissue. It's a non-invasive process and contributes to effective treatment.

19 services18 patients

Insertion of needle into vein for collection of blood sample 36415

This procedure involves inserting a small needle into a vein, typically in your arm, to collect a blood sample. It's a quick and simple process to help diagnose or monitor health conditions. You may feel a small prick, but discomfort is minimal.

16 services14 patients

Special radiation treatment 77470

Special radiation treatment is a medical procedure that uses high-energy rays to destroy or damage cancer cells. It's a targeted approach that aims to minimize harm to healthy tissues. The treatment duration varies based on individual health conditions.

14 services14 patients

Injection of biodegradable material next to prostate 55874

This procedure involves the introduction of a biodegradable substance near a gland located in the lower abdomen. This substance helps to create a barrier between the gland and nearby tissues, aiding in the precise delivery of treatment to the intended area.

11 services11 patients

Hospital Affiliations CMS Care Compare 2

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Inova Alexandria Hospital

Acute Care Hospitals · Alexandria, VA

4/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number490040

Location4320 Seminary RdAlexandria, VA 22304 · Alexandria City County

Emergency services Birthing friendly

Virginia Hospital Center

Acute Care Hospitals · Arlington, VA

5/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number490050

Location1701 North George Mason DriveArlington, VA 22205 · Arlington County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 22031 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$194.86 typical visit price

range $65.18 – $194.86

Typical copayment $48.71 (range $16.29 – $48.71)

Most-billed visit code 99205

Established Patient

$80.66 typical visit price

range $21.40 – $158.88

Typical copayment $20.16 (range $5.35 – $39.72)

Most-billed visit code 99213

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

91.96/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored through an Alternative Payment Model

Quality

81.4

Promoting Interoperability

100

Improvement Activities

Leave this field empty

Other Providers at the Same Location NPPES 2

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. HAROLD AGBAHIWE M.D.

Radiology (Radiation Oncology)

8613 ROUTE 29 STE 100N
FAIRFAX, VA 22031

Fairfax County (703) 934-4450

LEYLA MISSAGHI PA-C

Physician Assistant (Medical)

8613 ROUTE 29 STE 100N
FAIRFAX, VA 22031

Fairfax County (571) 350-8400

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Gregory Sibley's NPI number?

The NPI number for Gregory Sibley is 1043211360. It was assigned to this individual provider in the NPPES registry on August 9, 2005.

Where is Gregory Sibley located?

Gregory Sibley practices at 8613 Route 29 Ste 100N, Fairfax, VA 22031. The listed phone number is (571) 350-8400.

What is Gregory Sibley's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Radiation Oncology, with taxonomy code 2085R0001X.

Is Gregory Sibley enrolled in Medicare?

Yes. Gregory Sibley is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Is Gregory Sibley affiliated with any hospitals?

According to CMS data, Gregory Sibley is affiliated with Inova Alexandria Hospital and Virginia Hospital Center.

When was this NPI record last updated?

The NPPES record for Gregory Sibley was last updated on November 11, 2025. NPI Profile syncs with the weekly NPPES data releases published by CMS.