Peter J. Siefken, PA
Medical Physician Assistant · Amagansett, NY
Peter J. Siefken, PA is a medical physician assistant with a practice address in Amagansett, New York, and NPI 1144347261, issued on Mar 23, 2007. Check the license (New York 005732, as entered in NPPES) with the New York board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Peter J. Siefken
- Credential
- PA
- Primary taxonomy
- Medical Physician Assistant 363AM0700X
- License number
- 005732 NY
Self-reported in NPPES; status is on the state search - Practice location
- 518 Montauk Hwy, Amagansett, NY 11930
- Phone
- (631) 267-5373
- Enumerated
- Mar 23, 2007
- Record last updated
- Dec 5, 2016 (not updated in 10 years: call before relying on the address or phone)
- Fax
- (631) 267-5376
- Medicaid ID
- 02175175 NY
- Medicare enrollment
- Enrolled (PECOS I20160613000885); accepts Medicare assignment
- Medical or professional school
- State University Of New York At Stony Brook, School Of Medicine, 1996
- Entity
- Type 1 · individual
Also registered at 518 Montauk Hwy
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Shawn Cannon, DOInternal Medicine Physician1831276286
- Randi Cherill, PT, ATCPhysical Therapist1649213257
- Eugene Connolly, RPA-CMedical Physician Assistant1013121474
- Gina JenningsPhysical Therapy Assistant1861315178
- Annette Marshall, PTRehabilitation Practitioner1194880039
- Diane Schade, AGPCNP-BCAdult Health Nurse Practitioner1356765648
Verify Peter J. Siefken in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich New York board licenses this profession
Search for license 005732Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
54% fewer Medicare Part D claims than the average medical physician assistant in 2024
524 Medicare Part D claims for 334 beneficiaries, against an average of 1,148 among the 23,801 providers of this specialty who prescribed in Part D. 14 claims were for opioids.
Most prescribed
- Doxycycline Hyclate50 claims
- Azithromycin45 claims
- Cefdinir45 claims
- Prednisone33 claims
- Cephalexin30 claims
- Nitrofurantoin Mono-Macro30 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.
The MIPS final score for 2023 (Medicare payment program): 91.3 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- City Medical OF Upper East Side PLLCRiverhead, NY
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
2 medical physician assistant records list a practice address in Amagansett
They are 2 of the 21 NPPES records with a practice address in Amagansett, and 3,670 medical physician assistant records in New York.
All 2 in Amagansett → All 3,670 in New York → Every provider in Amagansett →
Other medical physician assistant records in New York
- Yesid Abad, PA CNew York, NY1205951399
- Stella Abayeva, P.A.Forest Hills, NY1124326467
- Amina Abdela, PA-CLatham, NY1891452496
- Hanan Abdelrahman, PA-CBrooklyn, NY1316348204
- Marwa AbdoAstoria, NY1467001081
- Avinell Abdool, PA-CBrooklyn, NY1558848572
- Devon AbeleMassapequa Park, NY1255817672
- Emily Abercrombie, P.A. - CNew York, NY1043601677
- Mandy Abram, RPA-CWilliamsville, NY1447547310
- Orchidea Abramowicz, RPA-CNew York, NY1396043188
Common questions
What is Peter J. Siefken, PA's NPI number?
Peter J. Siefken, PA's National Provider Identifier (NPI) is 1144347261, issued on Mar 23, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Peter J. Siefken, PA located?
The NPPES record lists a practice address at 518 Montauk Hwy, Amagansett, NY, 11930. Phone: (631) 267-5373. Providers update this record themselves, so call before visiting.
How can I verify Peter J. Siefken, PA's license?
NPPES lists New York license number 005732, as entered by the provider. Search the New York board that licenses this profession; the NPPES record confirms identity only.
How much does Peter J. Siefken, PA prescribe under Medicare Part D?
In 2024, Peter J. Siefken, PA had 524 Medicare Part D claims for 334 beneficiaries; the average among medical physician assistant prescribers was 1,148. Part D covers Medicare prescriptions only.
What is Peter J. Siefken, PA's MIPS final score?
The 2023 MIPS final score is 91.3 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.