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NICHOLAS JUNHYUK AHN M.D.
NPI 1912341447
Surgery in Stony Brook, NY

Active since April 26, 2013PECOS EnrolledAccepts Medicare Assignment
98.52/100
CMS Quality Rating
HEALTH SCIENCE TOWER LEVEL 19, ROOM 030, STONY BROOK, NY 11794(631) 444-1791 Get Directions Write a Review

NPPES record last updated: September 7, 2021. Verified against the NPPES registry weekly; last sync: August 23, 2026.

Record update history: Sep 7, 2021, Mar 13, 2020 (2 updates tracked since 2020).

About Nicholas Junhyuk Ahn M.d. NPPES

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

NICHOLAS JUNHYUK AHN M.D. (NPI 1912341447) is an individual surgery provider in Stony Brook, New York, licensed in New York (306605) and active in the NPI registry since April 2013. He is enrolled in Medicare PECOS, is affiliated with Suny/stony Brook University Hospital, and is a graduate of Pennsylvania State University College Of Medicine (2013).

NPPES Registry Identity

NPI1912341447
Entity TypeIndividualMale
Primary Taxonomy208600000X
Provider Legal NameNICHOLAS JUNHYUK AHNCredential: M.D.
Location AddressHEALTH SCIENCE TOWER LEVEL 19, ROOM 030Stony Brook, NY 11794-3412
Mailing AddressHealth Science Tower Level 18, Room 051Stony Brook, NY 11794-8191 · (631) 444-2704 · Fax (631) 444-7784
Phone(631) 444-1791
Sole ProprietorYes
Medical School CMSPennsylvania State University College Of MedicineGraduated 2013
Enumeration DateApril 26, 2013
Last NPPES UpdateSeptember 7, 20212 updates tracked since enumeration
NPPES CertifiedSeptember 7, 2021
✔ NPI 1912341447 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtySurgeryAllopathic & Osteopathic Physicians
Taxonomy Code208600000X
License✔ Licensed in NY · 306605
Definition
A general surgeon has expertise related to the diagnosis - preoperative, operative and postoperative management - and management of complications of surgical conditions in the following areas: alimentary tract; abdomen; breast, skin and soft tissue; endocrine system; head and neck surgery; pediatric surgery; surgical critical care; surgical oncology; trauma and burns; and vascular surgery. General surgeons increasingly provide care through the use of minimally invasive and endoscopic techniques. Many general surgeons also possess expertise in transplantation surgery, plastic surgery and cardiothoracic surgery.
Also ListedStudent in an Organized Health Care Education/Training ProgramTaxonomy 390200000X · License 63283
HEALTH SCIENCE TOWER LEVEL 19, ROOM 030, Stony Brook, NY 11794
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Nicholas Junhyuk Ahn 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 ID2163769613
PECOS Enrollment IDI20210920003281
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.

Areas of Expertise CMS Part B claims 6

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.

New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203
This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.
52 services52 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.
39 services28 patients
Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385
This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.
23 services23 patients
Diagnostic exam of large bowel using a flexible endoscope 45378
This procedure, known as a colonoscopy, involves using a flexible tube with a light and camera to examine the large intestine. It helps detect any abnormalities such as polyps or inflammation. It's a standard procedure to ensure gut health.
20 services20 patients
Diagnostic exam of anus using an endoscope 46600
This procedure involves using a thin, flexible instrument called an endoscope to examine the anal area. It helps detect any abnormal conditions or issues. It's a safe, routine exam performed by a healthcare professional.
17 services16 patients
Biopsy of large bowel using a flexible endoscope 45380
A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.
12 services12 patients

Hospital Affiliations CMS Care Compare

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

Suny/Stony Brook University Hospital

Acute Care Hospitals · Stony Brook, NY
4/5 CMS rating
OwnershipGovernment - State
CMS Certification Number330393
LocationHealth Sciences Center SunyStony Brook, NY 11794 · Suffolk County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 11794 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
$105.06 typical visit price
range $67.40 – $203.53
Typical copayment $26.26 (range $16.85 – $50.88)
Most-billed visit code 99203
Established Patient
$83.44 typical visit price
range $21.66 – $164.45
Typical copayment $20.86 (range $5.41 – $41.11)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

98.52/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored through an Alternative Payment Model
Quality82.85
Promoting Interoperability100
Improvement Activities40

Other Providers at the Same Location NPPES 2

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

ATHANASIOS ANGISTRIOTIS MD
Student in an Organized Health Care Education/Training Program
HEALTH SCIENCE TOWER LEVEL 19, ROOM 030
STONY BROOK, NY 11794
Suffolk County (631) 444-1791
KEVIN DUH
Surgery (Vascular Surgery)
HEALTH SCIENCE TOWER LEVEL 19, ROOM 030
STONY BROOK, NY 11794
Suffolk County (631) 444-1791

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 Nicholas Ahn's NPI number?

The NPI number for Nicholas Ahn is 1912341447. It was assigned to this individual provider in the NPPES registry on April 26, 2013.

Where is Nicholas Ahn located?

Nicholas Ahn practices at Health Science Tower Level 19, Room 030, Stony Brook, NY 11794. The listed phone number is (631) 444-1791.

What is Nicholas Ahn's specialty?

The primary specialty registered for this NPI is Surgery with taxonomy code 208600000X.

Is Nicholas Ahn enrolled in Medicare?

Yes. Nicholas Ahn 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.

Is Nicholas Ahn affiliated with any hospitals?

According to CMS data, Nicholas Ahn is affiliated with Suny/Stony Brook University Hospital.

When was this NPI record last updated?

The NPPES record for Nicholas Ahn was last updated on September 7, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years 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.