JAMES ALLAN KARLSON MD
NPI 1114915261
Orthopaedic Surgery - Sports Medicine in Cambridge, MA

Q: What is James Karlson's NPI number?

The NPI number for James Karlson is 1114915261. It was assigned to this individual provider in the NPPES registry on October 12, 2005.

Q: What is James Karlson's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Sports Medicine, with taxonomy code 207XX0005X.

Q: When was this NPI record last updated?

The NPPES record for James Karlson was last updated on August 7, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 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.

Active since October 12, 2005PECOS EnrolledAccepts Medicare Assignment

300 MOUNT AUBURN ST, SUITE 505, CAMBRIDGE, MA 02138(617) 491-6766(617) 491-2552 Get Directions Write a Review

NPPES record last updated: August 7, 2019. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Aug 7, 2019, Dec 6, 2017 (2 updates tracked since 2017).

On this page

About James Allan Karlson Md NPPES

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

JAMES ALLAN KARLSON MD (NPI 1114915261) is an individual sports medicine provider in Cambridge, Massachusetts, licensed in Massachusetts (74009) and active in the NPI registry since October 2005. He is enrolled in Medicare PECOS, is affiliated with Mount Auburn Hospital, and maintains a secondary practice location in Brighton.

NPPES Registry Identity

NPI1114915261

Entity TypeIndividualMale

Primary Taxonomy207XX0005X

Provider Legal NameJAMES ALLAN KARLSONCredential: MD

Location Address300 MOUNT AUBURN ST, SUITE 505Cambridge, MA 02138-5600

Mailing Address20 Guest St Ste 225Brighton, MA 02135-2065 · (617) 738-8642 · Fax (617) 202-4172

Phone(617) 491-6766

Fax(617) 491-2552

Sole ProprietorNo

Medical School CMSWarren Alpert Medical School Of Brown UniversityGraduated 1988

Enumeration DateOctober 12, 2005

Last NPPES UpdateAugust 7, 20192 updates tracked since enumeration

✔ NPI 1114915261 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOrthopaedic Surgery · Sports MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207XX0005X

License✔ Licensed in MA · 74009

Definition

An orthopaedic surgeon trained in sports medicine provides appropriate care for all structures of the musculoskeletal system directly affected by participation in sporting activity. This specialist is proficient in areas including conditioning, training and fitness, athletic performance and the impact of dietary supplements, pharmaceuticals, and nutrition on performance and health, coordination of care within the team setting utilizing other health care professionals, field evaluation and management, soft tissue biomechanics and injury healing and repair. Knowledge and understanding of the principles and techniques of rehabilitation, athletic equipment and orthotic devices enables the specialist to prevent and manage athletic injuries.

300 MOUNT AUBURN ST, Cambridge, MA 02138

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Secondary Practice Location 1

Location 120 Guest St Ste 225Brighton, MA 02135-2065 · Phone (617) 738-8642 · Fax (617) 202-4172

Other Identifiers 1

Medicaid3116956MA

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, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

James Allan Karlson 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 ID4981699485

PECOS Enrollment IDI20040415000400

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

Medicare enrollment records show James Karlson reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

President & Fellows Of Harvard College

0.7 mi

Multi-Specialty

75 MOUNT AUBURN ST
Cambridge, MA 02138

Reassigned Medicare billing, Massachusetts enrollment
170 clinicians in this Medicare group

NPI 1952366312 (617) 496-9506

Boston Orthopaedic And Spine LLC

6.5 mi

Orthopaedic Surgery

71 BORDER RD STE 200
Waltham, MA 02451

Reassigned Medicare billing, Massachusetts enrollment
27 clinicians in this Medicare group

NPI 1619507043 (617) 738-8642

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 14

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.

Injection, triamcinolone acetonide, preservative-free, extended-release, microsphere formulation, 1 mg J3304

Triamcinolone acetonide is a long-lasting, preservative-free steroid injection. It's delivered in tiny, slow-releasing particles (microspheres) to manage inflammation or related conditions. The dose given is 1 mg. It's generally safe with few side effects.

1,440 services20 patients

Injection, betamethasone acetate 3 mg and betamethasone sodium phosphate 3 mg J0702

This injection contains two medications, betamethasone acetate and betamethasone sodium phosphate. It is used to reduce inflammation and pain. It's given by a healthcare professional, often directly into the area causing discomfort.

1,061 services182 patients

Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3301

Triamcinolone acetonide is a medication used to reduce inflammation in the body. It's given as a 10 mg injection for conditions like allergies, arthritis, or skin problems. The injection helps to decrease swelling, redness, and itching.

584 services46 patients

Aspiration and/or injection of fluid from large joint 20610

This procedure involves using a needle to remove (aspiration) or introduce (injection) fluid into a large joint like the knee or hip. It can help diagnose conditions, relieve discomfort, or deliver medication directly to the joint.

332 services236 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.

248 services216 patients

Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

149 services116 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.

137 services137 patients

Shaving of part of shoulder bone and repair of ligament using an endoscope 29826

This procedure involves using a tiny camera, called an endoscope, to view and repair a damaged shoulder ligament. Simultaneously, a small portion of the shoulder bone is shaved to alleviate discomfort and improve movement. It's a minimally invasive technique that aids in a quicker recovery.

20 services20 patients

Partial removal of collar bone at shoulder using an endoscope 29824

This procedure involves the partial removal of the collar bone at the shoulder using an endoscope, a tool with a light and camera. It's done to relieve pain or improve shoulder movement. The surgeon makes small incisions, then uses the endoscope to guide their work.

19 services19 patients

New patient office or other outpatient visit with straightforward medical decision making, if using time, 15 minutes or more 99202

This service involves an initial visit to the doctor's office or other outpatient setting. It typically lasts between 15-29 minutes. The doctor will review your medical history, conduct a physical examination, and discuss your health concerns. It's a chance to establish your health baseline and address any immediate medical issues.

19 services19 patients

Repair of shoulder rotator cuff using an endoscope 29827

This procedure, known as arthroscopic rotator cuff repair, helps fix tears in the shoulder's rotator cuff. An endoscope, a small camera, is used to view the shoulder inside. Using small tools, the surgeon repairs the torn tissue. This minimally invasive approach often leads to a quicker recovery.

17 services17 patients

Removal of both knee cartilages using an endoscope 29880

This procedure, also known as bilateral knee arthroscopy, involves using a small camera (endoscope) to view and remove damaged cartilage from both knees. It's a minimally invasive surgery aimed at relieving pain and improving mobility.

17 services17 patients

Removal of knee cartilage using an endoscope 29881

This procedure, known as arthroscopic knee surgery, involves using a small camera (endoscope) to view the inside of your knee. Small instruments are used to remove damaged cartilage. This can help alleviate pain and improve knee function.

15 services15 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.

12 services12 patients

Hospital Affiliations CMS Care Compare

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

Mount Auburn Hospital

Acute Care Hospitals · Cambridge, MA

5/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number220002

Location330 Mount Auburn StreetCambridge, MA 02138 · Middlesex County

Emergency services Birthing friendly

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.

DR. MARGARET LOVE MCLAUGHLIN M.D.

Internal Medicine (Nephrology)

300 MOUNT AUBURN ST, SUITE 515
CAMBRIDGE, MA 02138

Middlesex County (617) 864-1571

RODERICK H CROCKER JR. MD

Urology

300 MOUNT AUBURN ST, STE 519
CAMBRIDGE, MA 02138

Middlesex County (617) 547-4400

DR. THOMAS CAUGHEY MD

Internal Medicine (Hematology & Oncology)

300 MOUNT AUBURN ST, HEMA/ONC
CAMBRIDGE, MA 02138

Middlesex County (617) 497-9646

MISS JOANNE BRUNY NP

Nurse Practitioner (Family)

300 MOUNT AUBURN ST
CAMBRIDGE, MA 02138

Middlesex County (617) 492-3500

CAMBRIDGE OTOLARYNGOLOGY

Otolaryngology

300 MOUNT AUBURN ST, SUITE 308
CAMBRIDGE, MA 02138

Middlesex County (617) 354-1010

KAREN L AHLERT M.D.

Surgery

300 MOUNT AUBURN ST, SUITE 407
CAMBRIDGE, MA 02138

Middlesex County (617) 868-7456

DR. SHILPA JOSHI DESAI MD

Ophthalmology

300 MOUNT AUBURN ST
CAMBRIDGE, MA 02138

Middlesex County (617) 499-5571

DR. JULIO C. AYALA MD

Internal Medicine (Gastroenterology)

300 MOUNT AUBURN ST
CAMBRIDGE, MA 02138

Middlesex County (617) 499-0026

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 James Karlson's NPI number?

The NPI number for James Karlson is 1114915261. It was assigned to this individual provider in the NPPES registry on October 12, 2005.

Where is James Karlson located?

James Karlson practices at 300 Mount Auburn St Suite 505, Cambridge, MA 02138. The listed phone number is (617) 491-6766.

What is James Karlson's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Sports Medicine, with taxonomy code 207XX0005X.

Is James Karlson enrolled in Medicare?

Yes. James Karlson 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 James Karlson's services?

According to the CMS Revalidation Reassignment List (October 2026 release), James Karlson reassigns Medicare benefits to 2 organizations: President & Fellows Of Harvard College (Cambridge, MA) and Boston Orthopaedic And Spine LLC (Waltham, MA). 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 James Karlson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does James Karlson accept?

Health plans from Anthem Blue Cross and Blue Shield list James Karlson 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 James Karlson affiliated with any hospitals?

According to CMS data, James Karlson is affiliated with Mount Auburn Hospital.

When was this NPI record last updated?

The NPPES record for James Karlson was last updated on August 7, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 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.