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KAREN THEO ISSELBACHER MD
NPI 1508822867
Internal Medicine in Wellesley, MA

Active since April 25, 2006PECOS EnrolledAccepts Medicare Assignment
70 HASTINGS ST, WELLESLEY, MA 02481(781) 444-3550(781) 444-3551 Get Directions Write a Review

NPPES record last updated: January 23, 2024. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Karen Theo Isselbacher Md NPPES

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

KAREN THEO ISSELBACHER MD (NPI 1508822867) is an individual internal medicine provider in Wellesley, Massachusetts, licensed in Massachusetts (59434) and active in the NPI registry since April 2006. She is enrolled in Medicare PECOS, is affiliated with Massachusetts General Hospital, and is a graduate of Boston University School Of Medicine (1985).

NPPES Registry Identity

NPI1508822867
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameKAREN THEO ISSELBACHERCredential: MD
Location Address70 HASTINGS STWellesley, MA 02481-5439
Mailing Address70 Hastings StWellesley, MA 02481-5439 · (781) 772-8500 · Fax (781) 772-8501
Phone(781) 444-3550
Fax(781) 444-3551
Sole ProprietorNo
Medical School CMSBoston University School Of MedicineGraduated 1985
Enumeration DateApril 25, 2006
Last NPPES UpdateJanuary 23, 2024
NPPES CertifiedJanuary 23, 2024
✔ NPI 1508822867 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in MA · 59434
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.
70 HASTINGS ST, Wellesley, MA 02481
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Accepted Insurance

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

Karen Theo Isselbacher Md 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 ID5193732220
PECOS Enrollment IDI20060315000417
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 Reassignment

Medicare enrollment records show Karen Isselbacher reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Private Health Care Group, LLC
Same address
Internal Medicine
70 HASTINGS ST
Wellesley, MA 02481
  • Reassigned Medicare billing, Massachusetts enrollment
  • 7 clinicians in this Medicare group
NPI 1053680108 (781) 772-5500

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 11

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.

Insertion of needle into vein for collection of blood sample 36415
This procedure involves inserting a small needle into a vein, typically in your arm, to collect a blood sample. It's a quick and simple process to help diagnose or monitor health conditions. You may feel a small prick, but discomfort is minimal.
106 services52 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
95 services58 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.
94 services60 patients
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit G0439
An annual wellness visit is a yearly appointment with your primary care provider to create or update a personalized prevention plan. This plan helps prevent illness based on your current health and risk factors. It's a subsequent visit, meaning it follows an initial assessment.
62 services62 patients
Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 93000
An electrocardiogram (ECG) is a non-invasive test that records your heart's electrical activity. Using 12 leads attached to your body, it captures data to help identify heart conditions. A doctor interprets the results and provides a report.
59 services53 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.
50 services35 patients

Hospital Affiliations CMS Care Compare 5

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

Massachusetts General Hospital

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220071
Location55 Fruit StreetBoston, MA 02114 · Suffolk County
Emergency services Birthing friendly

Emerson Hospital -

Acute Care Hospitals · W Concord, MA
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220084
Location133 Old Road To 9 Acre CornerW Concord, MA 01742 · Middlesex County
Emergency services Birthing friendly

Newton-Wellesley Hospital

Acute Care Hospitals · Newton, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220101
Location2014 Washington StreetNewton, MA 02462 · Middlesex County
Emergency services Birthing friendly

Brigham And Women's Hospital

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220110
Location75 Francis StreetBoston, MA 02115 · Suffolk County
Emergency services Birthing friendly

Faulkner Hospital-Brigham And Women's

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220119
Location1153 Centre StreetBoston, MA 02130 · Suffolk County
Emergency services

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02481 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
$144.11 typical visit price
range $63.72 – $189.86
Typical copayment $36.02 (range $15.93 – $47.46)
Most-billed visit code 99204
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
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 3

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

PRIVATE HEALTH CARE GROUP, LLC
Internal Medicine
70 HASTINGS ST
WELLESLEY, MA 02481
Norfolk County (781) 772-5500
CHRISTINE M HARRINGTON M.D.
Internal Medicine
70 HASTINGS ST
WELLESLEY, MA 02481
Norfolk County (781) 772-8300
DR. LI TSO M.D.
Internal Medicine
70 HASTINGS ST
WELLESLEY, MA 02481
Norfolk County (781) 772-8100

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 Karen Isselbacher's NPI number?

The NPI number for Karen Isselbacher is 1508822867. It was assigned to this individual provider in the NPPES registry on April 25, 2006.

Where is Karen Isselbacher located?

Karen Isselbacher practices at 70 Hastings St, Wellesley, MA 02481. The listed phone number is (781) 444-3550.

What is Karen Isselbacher's specialty?

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

Is Karen Isselbacher enrolled in Medicare?

Yes. Karen Isselbacher 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 organization bills Medicare for Karen Isselbacher's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Karen Isselbacher reassigns Medicare benefits to Private Health Care Group, LLC (Wellesley, MA). The 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 Karen Isselbacher's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Karen Isselbacher accept?

Health plans from Anthem Blue Cross and Blue Shield and Taro Health list Karen Isselbacher 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 Karen Isselbacher affiliated with any hospitals?

According to CMS data, Karen Isselbacher is affiliated with Massachusetts General Hospital, Emerson Hospital -, Newton-Wellesley Hospital, Brigham And Women's Hospital and Faulkner Hospital-Brigham And Women's.

When was this NPI record last updated?

The NPPES record for Karen Isselbacher was last updated on January 23, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.