John Harold Giesler, M.D.
Radiation Oncology Physician · Riverdale, GA
John Harold Giesler, M.D. is a radiation oncology physician with a practice address in Riverdale, Georgia, and NPI 1649261926, issued on Nov 4, 2005. Check the license (Georgia 35882, as entered in NPPES) on the Georgia Composite Medical Board; the Medicare figures below come from public CMS files.
- Name
- John Harold Giesler
- Credential
- M.D.
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License number
- 35882 GA
Self-reported in NPPES; status is on the state search - Practice location
- 255 Professional CT, Riverdale, GA 30274
- Phone
- (770) 997-8424
- Enumerated
- Nov 4, 2005
- Record last updated
- Jul 15, 2010 (not updated in 16 years: call before relying on the address or phone)
- Medicaid IDs
- 00582887C GA
00582887B GA
00582887D GA - Medicare enrollment
- Enrolled (PECOS I20040325000749); accepts Medicare assignment
- Medical or professional school
- Ohio Medical University, 1987
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 180 in Georgia → Look up another NPI →
Also registered at 255 Professional CT
A shared address usually means a shared clinic or building; it does not show who employs whom.
- J. Warner Ray, MDRadiation Oncology Physician1104871326
Verify John Harold Giesler in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersGeorgia Composite Medical Board
Search for license 35882Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
89% more Medicare Part D claims than the average radiation oncology physician in 2024
253 Medicare Part D claims for 119 beneficiaries, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D. Brand-name drugs were 15% of claims. 55 claims were for opioids.
Most prescribed
- Tamsulosin Hcl51 claims
- Oxycodone-Acetaminophen46 claims
- Silver Sulfadiazine19 claims
- Lorazepam13 claims
- Doxazosin Mesylate12 claims
- Ssd12 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $15.73
1 payment: food and beverage; the largest payer was Brainlab, Inc. The 3,275 providers of this specialty with any payment received $1,897.85 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Therapeutic Radiation Oncology, PCStockbridge, GA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
John Harold Giesler among 180 radiation oncology physician records in Georgia
John Harold Giesler, M.D. is one of 180 radiation oncology physician records with a practice address in Georgia. 85% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 86% newer
- In a Medicare fileYes · 85% of these records are
- In the CMS Doctors and Clinicians fileYes · 79% of these records are
- Graduated1987 · median 2004 among the 142 with a school on file
- Record last updated2010 · 62% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a Georgia practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in Georgia
There are 180 radiation oncology physician records in Georgia.
All 180 in Georgia → Every provider in Riverdale → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- J. Warner Ray, MDRiverdale, GA 302741104871326
- Charles Woods, M.D.Riverdale, GA 302741679739825
- Kim Neisler, MDStockbridge, GA 302811093760217
- Sasha Wahab, MD, MAStockbridge, GA 302811053438762
- Christopher Williamson, MDStockbridge, GA 302811326675208
- Salman Eraj, MDNewnan, GA 302651891282463
- Elesyia Outlaw-Evans, MDNewnan, GA 302651821115304
- Diana Santiago, MDNewnan, GA 302651073552196
Common questions
What is John Harold Giesler, M.D.'s NPI number?
John Harold Giesler, M.D.'s National Provider Identifier (NPI) is 1649261926, issued on Nov 4, 2005. An NPI identifies a provider in billing; it is not a license.
Where is John Harold Giesler, M.D. located?
The NPPES record lists a practice address at 255 Professional CT, Riverdale, GA, 30274. Phone: (770) 997-8424. Providers update this record themselves, so call before visiting.
How can I verify John Harold Giesler, M.D.'s license?
NPPES lists Georgia license number 35882, as entered by the provider. Search the Georgia Composite Medical Board at https://medicalboard.georgia.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John Harold Giesler, M.D. prescribe under Medicare Part D?
In 2024, John Harold Giesler, M.D. had 253 Medicare Part D claims for 119 beneficiaries; the average among radiation oncology physician prescribers was 134. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.