Ryan Patrick Casarella, M.D.
Emergency Medicine Physician · Greenwich, CT
Ryan Patrick Casarella, M.D. is an emergency medicine physician with a practice address in Greenwich, Connecticut, and NPI 1740643998, issued on Apr 4, 2016. Check the license on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Ryan Patrick Casarella
- Credential
- M.D.
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License numbers
- 314567-01 NY
19025 NV
Self-reported in NPPES; status is on the state search - Practice location
- 5 Perryridge RD, Greenwich, CT 06830
- Phone
- (203) 863-3000
- Enumerated
- Apr 4, 2016
- Record last updated
- Feb 11, 2025
- Medicare enrollment
- Enrolled (PECOS I20250214001205); accepts Medicare assignment
- Medical or professional school
- University Of Massachusetts Medical School, 2016
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 846 in Connecticut → Look up another NPI →
Also registered at 5 Perryridge RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Diana Adams, M.D.Maternal & Fetal Medicine Physician1255300653
- Saheeb AhmedStudent in an Organized Health Care Education/Training Program1326626748
- Rachel Alfandre, LCSWClinical Social Worker1497077259
- Vicki Altmeyer, M.D.Anatomic Pathology & Clinical Pathology Physician1700807898
Verify Ryan Patrick Casarella in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining BoardCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
15% fewer Medicare Part D claims than the average emergency medicine physician in 2024
193 Medicare Part D claims for 113 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 11 claims were for opioids.
Most prescribed
- Naproxen42 claims
- Amoxicillin-Clavulanate Potass23 claims
- Methylprednisolone20 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 one group practice
- Greenwich HospitalGreenwich, CT
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Ryan Patrick Casarella among 846 emergency medicine physician records in Connecticut
Ryan Patrick Casarella, 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 2016, is newer than 73% of them.
- NPI issued2016 · 73% of these records are older, 24% newer
- In a Medicare fileYes · 86% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated2016 · median 2011 among the 574 with a school on file
- Record last updated2025 · 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).
Emergency Medicine Physician providers in Connecticut
There are 846 emergency medicine physician records in Connecticut.
All 846 in Connecticut → Every provider in Greenwich → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Maria Brea, M.D.Greenwich, CT 068301508809161
- J. Allen Britvan, M.DGreenwich, CT 068301376566042
- Michael Canter, M.D.Greenwich, CT 068301558381483
- Robert Chang, MDGreenwich, CT 068301760581672
- Christopher Davison, M.D.Greenwich, CT 068301225051857
- Servando De Los Angeles, M.D.Greenwich, CT 068301831119619
- Stacey Donegan, M.D.Greenwich, CT 068301174546709
- Shideh Imanian-Parsa, M.D.Greenwich, CT 068301124049945
Common questions
What is Ryan Patrick Casarella, M.D.'s NPI number?
Ryan Patrick Casarella, M.D.'s National Provider Identifier (NPI) is 1740643998, issued on Apr 4, 2016. An NPI identifies a provider in billing; it is not a license.
Where is Ryan Patrick Casarella, M.D. located?
The NPPES record lists a practice address at 5 Perryridge RD, Greenwich, CT, 06830. Phone: (203) 863-3000. Providers update this record themselves, so call before visiting.
How can I verify Ryan Patrick Casarella, M.D.'s license?
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 Ryan Patrick Casarella, M.D. prescribe under Medicare Part D?
In 2024, Ryan Patrick Casarella, M.D. had 193 Medicare Part D claims for 113 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.