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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

JONATHAN GAMSS M.D.
NPI 1598922874
Internal Medicine in Mount Kisco, NY

Active since May 22, 2008PECOS Enrolled
400 E MAIN ST, NORTHERN WESTCHESTER HOSPITAL, MOUNT KISCO, NY 10549(914) 666-1680(914) 666-1965 Get Directions Write a Review

NPPES record last updated: October 21, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Nov 18, 2024, Nov 20, 2020 (2 updates tracked since 2020).

About Jonathan Gamss M.d. NPPES

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

JONATHAN GAMSS M.D. (NPI 1598922874) is an individual internal medicine provider in Mount Kisco, New York, licensed in New York (246486) and active in the NPI registry since May 2008. He is enrolled in Medicare PECOS, is affiliated with Clara Maass Medical Center, and maintains 4 additional practice locations.

NPPES Registry Identity

NPI1598922874
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameJONATHAN GAMSSCredential: M.D.
Location Address400 E MAIN ST, NORTHERN WESTCHESTER HOSPITALMount Kisco, NY 10549-3417
Mailing Address400 E Main St, Northern Westchester Hospital, Medical Affairs OfficeMount Kisco, NY 10549-3417 · (914) 666-1680 · Fax (914) 666-1965
Phone(914) 666-1680
Fax(914) 666-1965
Sole ProprietorNo
Medical School CMSOtherGraduated 2004
Enumeration DateMay 22, 2008
Last NPPES UpdateOctober 21, 20262 updates tracked since enumeration
NPPES CertifiedOctober 21, 2026
✔ NPI 1598922874 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Licenses✔ Licensed in NY · 246486✔ Licensed in CO · DR.0076561✔ Licensed in FL · ME178297
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Also ListedEmergency MedicineTaxonomy 207P00000X · License 25MA08623200 (NJ)
400 E MAIN ST, Mount Kisco, NY 10549
Open in Google Maps ↗

Secondary Practice Locations 4

Location 1391 E 149th St Ste 403Bronx, NY 10455-3907 · Phone (718) 819-6144 · Fax (718) 819-6145
Location 21441 E Fletcher Ave Ste 113Tampa, FL 33612-3670 · Phone (718) 819-6144 · Fax (718) 819-6145
Location 310465 Melody Dr Ste 123Northglenn, CO 80234-4101 · Phone (718) 819-6144 · Fax (718) 819-6145
Location 43611 14th Ave Ste 550Brooklyn, NY 11218-3773 · Phone (718) 819-6144 · Fax (718) 819-6145

Other Identifiers 1

Medicaid03040282NY

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Oscar Health.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Jonathan Gamss 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 ID345311015
PECOS Enrollment IDI20080624000502, I20100325000556
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.

Medicare Billing Reassignments

12

Medicare enrollment records show Jonathan Gamss reassigns Medicare billing to 12 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Northern Westchester Hospital Association
Same address
Emergency Medicine
400 E MAIN ST
Mount Kisco, NY 10549
  • Reassigned Medicare billing, New York enrollment
  • 76 clinicians in this Medicare group
NPI 1679641237 (914) 666-1254
Gamss Medical Consulting Nj PC
24 mi
Emergency Medicine
40 DUDLEY DR
Bergenfield, NJ 07621
  • Reassigned Medicare billing, New Jersey enrollment
NPI 1710860176 (845) 782-0000
Vladimir Zelenko M.D. P.C.
26 mi
Family Medicine
3 HAMASPIK WAY
Monroe, NY 10950
  • Reassigned Medicare billing, New York enrollment
  • Medicare enrollment name: Vladimir Zelenko MD PC
  • 5 clinicians in this Medicare group
NPI 1063669562 (845) 782-0000
Gamms LLC
27 mi
Clinic/Center
3 HAMASPIK WAY UNIT 11
Monroe, NY 10950
  • Reassigned Medicare billing, New York enrollment
NPI 1760347009 (845) 782-0000
Gamss Medical Consulting PC
27 mi
Emergency Medicine
3 HAMASPIK WAY UNIT 11
Monroe, NY 10950
  • Reassigned Medicare billing, New York enrollment
NPI 1275415820 (845) 782-0000
North Shore-Lij Medical PC
28 mi
Urology
1010 NORTHERN BLVD STE 110
Great Neck, NY 11021
  • Reassigned Medicare billing, New York enrollment
  • 9,353 clinicians in this Medicare group
NPI 1053688572 (516) 321-7400
Gamss Health Urgent Medicine PC
41 mi
Internal Medicine
3611 14TH AVE STE 550
Brooklyn, NY 11218
  • Reassigned Medicare billing, New York enrollment
  • 13 clinicians in this Medicare group
NPI 1447078738 (718) 819-6144
464 Bay Ridge Medical PLLC
42 mi
Internal Medicine
466 BAY RIDGE AVE
Brooklyn, NY 11220
  • Reassigned Medicare billing, New York enrollment
  • 18 clinicians in this Medicare group
NPI 1912568981 (718) 491-2003
Rwjbh Observation Associates LLC
42 mi
Emergency Medicine
94 OLD SHORT HILLS RD
Livingston, NJ 07039
  • Reassigned Medicare billing, New Jersey enrollment
  • 1,913 clinicians in this Medicare group
NPI 1760095806 (888) 724-7123
Rwjbh Emergency Medicine Associates, LLC
61 mi
Emergency Medicine
3 EXECUTIVE DR, STE 400
Somerset, NJ 08873
  • Reassigned Medicare billing, New Jersey enrollment
  • 1,557 clinicians in this Medicare group
NPI 1912510041 (732) 867-9618

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 8

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.

Emergency department visit with high level of medical decision making 99285
An emergency department visit for severe conditions is when you urgently seek medical help due to serious health issues. These could be severe injuries, breathing problems, unbearable pain, or sudden severe illness. Doctors and nurses will provide immediate care to stabilize your condition.
430 services401 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.
78 services61 patients
Emergency department visit with moderate level of medical decision making 99284
An emergency department visit for a high-severity issue means you're experiencing a serious health problem that needs immediate attention. This could be a severe injury, serious illness, or life-threatening condition. Medical professionals will provide urgent care to stabilize your condition.
71 services66 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.
58 services52 patients
Critical care, first 30-74 minutes 99291
Critical care involves immediate and constant attention by a team of specially-trained health professionals. It's for patients with life-threatening conditions, requiring first 30-74 minutes of intense monitoring and treatment.
33 services32 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
28 services26 patients

Hospital Affiliations CMS Care Compare

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

Clara Maass Medical Center

Acute Care Hospitals · Belleville, NJ
1/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number310009
LocationOne Clara Maass DriveBelleville, NJ 07109 · Essex County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 10549 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
$154.28 typical visit price
range $67.40 – $203.53
Typical copayment $38.57 (range $16.85 – $50.88)
Most-billed visit code 99204
Established Patient
$117.62 typical visit price
range $21.66 – $164.45
Typical copayment $29.40 (range $5.41 – $41.11)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

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

MS. MICHAEL ARLIA MD
Anesthesiology
400 E MAIN ST, NORTHERN WESTCHESTER HOSPITAL
MOUNT KISCO, NY 10549
Westchester County (914) 666-1691
DR. HERBERTH BALSELLS D.O.
Emergency Medicine
400 E MAIN ST
MOUNT KISCO, NY 10549
Westchester County (914) 666-1254
SABINA MUSOVIC SEFOVIC MD
Anesthesiology (Critical Care Medicine)
400 E MAIN ST
MOUNT KISCO, NY 10549
Westchester County (914) 666-1200
DR. ANDREW MONIK MOGGA MD
Student in an Organized Health Care Education/Training Program
400 E MAIN ST
MOUNT KISCO, NY 10549
Westchester County (914) 666-1931
MAZEN T KHALIFEH MD
Pediatrics (Neonatal-Perinatal Medicine)
400 E MAIN ST, NORTHERN WESTCHESTER HOSPITAL
MOUNT KISCO, NY 10549
Westchester County (914) 666-1862
NANDINI ANANDU MD
Internal Medicine
400 E MAIN ST, NORTHERN WESTCHESTER HOSPITAL
MOUNT KISCO, NY 10549
Westchester County (914) 666-1200
ANISHA DUVVI
Student in an Organized Health Care Education/Training Program
400 E MAIN ST
MOUNT KISCO, NY 10549
Westchester County (914) 666-1931
KAREN S ARTHUR MD
Surgery
400 E MAIN ST, NWH NORTH BUILDING 1ST FLOOR
MOUNT KISCO, NY 10549
Westchester County (914) 242-7640

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 Jonathan Gamss's NPI number?

The NPI number for Jonathan Gamss is 1598922874. It was assigned to this individual provider in the NPPES registry on May 22, 2008.

Where is Jonathan Gamss located?

Jonathan Gamss practices at 400 E Main St Northern Westchester Hospital, Mount Kisco, NY 10549. The listed phone number is (914) 666-1680.

What is Jonathan Gamss's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Jonathan Gamss enrolled in Medicare?

Yes. Jonathan Gamss 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.

Which organizations bill Medicare for Jonathan Gamss's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Jonathan Gamss reassigns Medicare benefits to 12 organizations: Northern Westchester Hospital Association (Mount Kisco, NY), Gamss Medical Consulting Nj PC (Bergenfield, NJ), Vladimir Zelenko M.D. P.C. (Monroe, NY), Gamms LLC (Monroe, NY), Gamss Medical Consulting PC (Monroe, NY) and 7 more organizations, listed in the Medicare section above. Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Jonathan Gamss's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Jonathan Gamss accept?

Health plans from Oscar Health list Jonathan Gamss as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Jonathan Gamss affiliated with any hospitals?

According to CMS data, Jonathan Gamss is affiliated with Clara Maass Medical Center.

When was this NPI record last updated?

The NPPES record for Jonathan Gamss was last updated on October 21, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.