Gregory S. Johnston, M.D.
Emergency Medicine Physician · New London, CT
Gregory S. Johnston, M.D. is an emergency medicine physician with a practice address in New London, Connecticut, and NPI 1457344137, issued on Aug 26, 2005. Check the license (Connecticut 64109, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Gregory S. Johnston
- Credential
- M.D.
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- 64109 CT
Self-reported in NPPES; status is on the state search - Practice location
- 365 Montauk Ave, New London, CT 06320
- Phone
- (860) 442-0711
- Enumerated
- Aug 26, 2005
- Record last updated
- Oct 29, 2024
- Medicare enrollment
- Enrolled (PECOS I20260217002023); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 846 in Connecticut → Look up another NPI →
Also registered at 365 Montauk Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Gregory S. Johnston in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 64109Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
36% fewer Medicare Part D claims than the average emergency medicine physician in 2024
144 Medicare Part D claims for 105 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 26 claims were for opioids.
Most prescribed
- Cephalexin22 claims
- Oxycodone-Acetaminophen20 claims
- Prednisone11 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.
Bills Medicare through 3 group practices
- Emergency Medicine Services OF NH, LLCManchester, NH
- Emergency Professional Services PCPhoenix, AZ
- Hospitalist Medicine Physicians OF New Mexico - Clovis LLCHobbs, NM
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gregory S. Johnston among 846 emergency medicine physician records in Connecticut
Gregory S. Johnston, M.D. is one of 846 emergency medicine physician records with a practice address in Connecticut. 86% 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, 94% newer
- In a Medicare fileYes · 86% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated1990 · median 2011 among the 574 with a school on file
- Record last updated2024 · 57% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207P00000X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
35 emergency medicine physician records list a practice address in New London
They are 35 of the 1,218 NPPES records with a practice address in New London, and 846 emergency medicine physician records in Connecticut.
All 846 in Connecticut → Every provider in New London → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Nader Bahadory, DONew London, CT 063201790894319
- David Bouslough, MDNew London, CT 063201407870330
- Russell Firman, MDNew London, CT 063201124191465
- Whitney FisherNew London, CT 063201508088659
- Katherine Hesse, MDNew London, CT 063201548235088
- Ashok Maheshwari, MDNew London, CT 063201760543813
- Samuel Maryles, MDNew London, CT 063201013064591
- Oliver Mayorga, M.D.New London, CT 063201720054661
Common questions
What is Gregory S. Johnston, M.D.'s NPI number?
Gregory S. Johnston, M.D.'s National Provider Identifier (NPI) is 1457344137, issued on Aug 26, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Gregory S. Johnston, M.D. located?
The NPPES record lists a practice address at 365 Montauk Ave, New London, CT, 06320. Phone: (860) 442-0711. Providers update this record themselves, so call before visiting.
How can I verify Gregory S. Johnston, M.D.'s license?
NPPES lists Connecticut license number 64109, as entered by the provider. Search the Connecticut Medical Examining Board at https://www.elicense.ct.gov/Lookup/LicenseLookup.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gregory S. Johnston, M.D. prescribe under Medicare Part D?
In 2024, Gregory S. Johnston, M.D. had 144 Medicare Part D claims for 105 beneficiaries; the average among emergency medicine physician prescribers was 226. 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.