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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.

KELLY J OCALLAHAN M.D.
NPI 1427056795
Internal Medicine - Gastroenterology in Worcester, MA

Active since July 12, 2005PECOS EnrolledAccepts Medicare Assignment
100 CENTRAL ST, FLOOR 4, WORCESTER, MA 01608(508) 831-0708(508) 831-0272 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 16, 2026.

About Kelly J Ocallahan M.d. NPPES

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

KELLY J OCALLAHAN M.D. (NPI 1427056795) is an individual gastroenterology provider in Worcester, Massachusetts, licensed in Massachusetts (159560) and active in the NPI registry since July 2005. She is enrolled in Medicare PECOS, is affiliated with Umass Memorial Health - Harrington Hospital, and is a graduate of University Of Massachusetts Medical School (1993).

NPPES Registry Identity

NPI1427056795
Entity TypeIndividualFemale
Primary Taxonomy207RG0100X
Provider Legal NameKELLY J OCALLAHANCredential: M.D.
Location Address100 CENTRAL ST, FLOOR 4Worcester, MA 01608-1209
Mailing Address100 Central St, Floor 4Worcester, MA 01608-1209 · (508) 831-0708 · Fax (508) 831-0272
Phone(508) 831-0708
Fax(508) 831-0272
Sole ProprietorNo
Medical School CMSUniversity Of Massachusetts Medical SchoolGraduated 1993
Enumeration DateJuly 12, 2005
Last NPPES UpdateJuly 13, 2026
✔ NPI 1427056795 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians
Taxonomy Code207RG0100X
License✔ Licensed in MA · 159560
Definition
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.
100 CENTRAL ST, Worcester, MA 01608
Open in Google Maps ↗

Other Identifiers 1

Medicaid3201601MA

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield.Insurance ›

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

Kelly J Ocallahan 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 ID648269027
PECOS Enrollment IDI20040511000166
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 9

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.

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.
138 services138 patients
Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239
This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.
122 services121 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.
108 services107 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.
108 services87 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.
30 services28 patients
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.
27 services27 patients

Hospital Affiliations CMS Care Compare 3

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

Umass Memorial Health - Harrington Hospital

Acute Care Hospitals · Southbridge, MA
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220019
Location100 South StreetSouthbridge, MA 01550 · Worcester County
Emergency services

Umass Memorial Medical Center/University Campus

Acute Care Hospitals · Worcester, MA
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220163
Location55 Lake Avenue NorthWorcester, MA 01655 · Worcester County
Emergency services Birthing friendly

St Vincent Hospital

Acute Care Hospitals · Worcester, MA
2/5 CMS rating
OwnershipProprietary
CMS Certification Number220176
Location123 Summer StreetWorcester, MA 01608 · Worcester County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 01608 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
$134.47 typical visit price
range $58.86 – $177.36
Typical copayment $33.61 (range $14.71 – $44.34)
Most-billed visit code 99204
Established Patient
$103.48 typical visit price
range $19.11 – $144.84
Typical copayment $25.87 (range $4.77 – $36.21)
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 4

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

WORCESTER DERMATOLOGY ASSOCIATES, P.C.
Specialist
100 CENTRAL ST
WORCESTER, MA 01608
Worcester County (508) 754-3823
NEW ENGLAND GASTROENTEROLOGY ASSOCIATES, PC
Internal Medicine (Gastroenterology)
100 CENTRAL ST, 4TH FLOOR
WORCESTER, MA 01608
Worcester County (508) 831-6708
KYUNG H KIM M.D.
Internal Medicine (Gastroenterology)
100 CENTRAL ST, 4TH FLOOR
WORCESTER, MA 01608
Worcester County (508) 831-0708
ADULT MEDICINE PHYSICIANS, LLC
Internal Medicine
100 CENTRAL ST, STE 4
WORCESTER, MA 01608
Worcester County (508) 363-3616

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 Kelly Ocallahan's NPI number?

The NPI number for Kelly Ocallahan is 1427056795. It was assigned to this individual provider in the NPPES registry on July 12, 2005.

Where is Kelly Ocallahan located?

Kelly Ocallahan practices at 100 Central St Floor 4, Worcester, MA 01608. The listed phone number is (508) 831-0708.

What is Kelly Ocallahan's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Kelly Ocallahan enrolled in Medicare?

Yes. Kelly Ocallahan 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.

What insurance does Kelly Ocallahan accept?

Health plans from Anthem Blue Cross and Blue Shield list Kelly Ocallahan 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 Kelly Ocallahan affiliated with any hospitals?

According to CMS data, Kelly Ocallahan is affiliated with Umass Memorial Health - Harrington Hospital, Umass Memorial Medical Center/University Campus and St Vincent Hospital.

When was this NPI record last updated?

The NPPES record for Kelly Ocallahan was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 37 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.