NATHAN E. RIDDELL M.D.
NPI 1245670983
Internal Medicine - Cardiovascular Disease in Worcester, MA

Q: What is Nathan Riddell's NPI number?

The NPI number for Nathan Riddell is 1245670983. It was assigned to this individual provider in the NPPES registry on June 26, 2013.

Q: What is Nathan Riddell's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Cardiovascular Disease, with taxonomy code 207RC0000X.

Q: When was this NPI record last updated?

The NPPES record for Nathan Riddell was last updated on December 8, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 months 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 June 26, 2013PECOS EnrolledAccepts Medicare Assignment

55 LAKE AVE N, WORCESTER, MA 01655(508) 334-1000 Get Directions Write a Review

NPPES record last updated: December 8, 2025. Verified against the NPPES registry weekly; last sync: October 04, 2026.

Record update history: Dec 8, 2025, Mar 14, 2025 (2 updates tracked since 2025).

On this page

About Nathan E. Riddell M.d. NPPES

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

NATHAN E. RIDDELL M.D. (NPI 1245670983) is an individual cardiovascular disease provider in Worcester, Massachusetts, licensed in Massachusetts (273386) and active in the NPI registry since June 2013. He is enrolled in Medicare PECOS, is affiliated with Lowell General Hospital, and maintains a secondary practice location in Lowell.

NPPES Registry Identity

NPI1245670983

Entity TypeIndividualMale

Primary Taxonomy207RC0000X

Provider Legal NameNATHAN E. RIDDELLCredential: M.D.

Location Address55 LAKE AVE NWorcester, MA 01655-0002

Mailing Address55 Lake Ave NWorcester, MA 01655-0002 · (508) 334-1000

Phone(508) 334-1000

Sole ProprietorNo

Medical School CMSOtherGraduated 2013

Enumeration DateJune 26, 2013

Last NPPES UpdateDecember 8, 20252 updates tracked since enumeration

NPPES CertifiedDecember 8, 2025

✔ NPI 1245670983 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Cardiovascular DiseaseAllopathic & Osteopathic Physicians

Taxonomy Code207RC0000X

License✔ Licensed in MA · 273386

Definition

An internist who specializes in diseases of the heart and blood vessels and manages complex cardiac conditions such as heart attacks and life-threatening, abnormal heartbeat rhythms.

Also ListedInternal MedicineTaxonomy 207R00000X · License 256554 (MA)

55 LAKE AVE N, Worcester, MA 01655

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Secondary Practice Location 1

Location 11115 Westford St Ste 2Lowell, MA 01851-2853 · Phone (351) 221-7080

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

Nathan E. Riddell 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 ID2062643489

PECOS Enrollment IDI20180809005466

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 26

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.

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 93010

A routine electrocardiogram (ECG) with 12 leads is a simple, non-invasive test that records the electrical activity of your heart. It helps in identifying heart conditions by detecting irregularities in your heart rhythms. The results are interpreted and a report is provided.

833 services670 patients

Ultrasound of heart with color-depicted blood flow, rate, direction and valve function 93306

This is a heart ultrasound, also known as an echocardiogram. It uses sound waves to create pictures of your heart, showing how blood flows through it. The color depicts the blood flow's speed and direction. It also checks the heart's valves to ensure they're working properly.

254 services251 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.

250 services244 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

103 services80 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.

85 services78 patients

Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222

Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.

64 services64 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.

51 services46 patients

Use of a drug to induce depression of consciousness by physician performing a procedure (5 years or older), initial 15 minutes 99152

This procedure involves a doctor administering a medication to reduce your consciousness during a procedure. This helps in managing discomfort and anxiety. The initial application lasts for 15 minutes and is for individuals aged 5 years or older.

50 services47 patients

Ultrasound of heart, follow-up 93308

A follow-up ultrasound of the heart, also known as an echocardiogram, is a non-invasive test that uses sound waves to create images of your heart. It helps doctors monitor your heart's function and structures after initial assessment or treatment.

40 services36 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.

39 services26 patients

Insertion of tube in left lower heart chamber and coronary artery for diagnosis with review by radiologist 93458

This procedure involves placing a tube into your left lower heart chamber and coronary artery. It helps doctors diagnose heart conditions by allowing them to view these areas in detail. A radiologist will review the images to ensure accurate diagnosis.

34 services34 patients

Insertion of stents with balloon dilation of coronary artery or branch, single artery or branch 92928

This procedure involves placing a small, mesh tube (stent) in your coronary artery to keep it open. A balloon is used to expand the stent and artery, improving blood flow to your heart. It's typically done for a single artery or branch.

28 services21 patients

Ultrasound of heart with color-depicted blood flow, rate, direction and valve function 93306

28 services28 patients

Insertion of tube in right heart chambers and coronary artery for diagnosis with review by radiologist 93456

This procedure involves placing a small tube into your right heart chambers and coronary artery. It helps in diagnosing heart conditions. A radiologist will review the images obtained for accurate results. It's a standard, safe process.

27 services27 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

27 services25 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.

26 services26 patients

Replacement of aortic valve through the skin and femoral artery 33361

This procedure, known as Transcatheter Aortic Valve Replacement (TAVR), involves replacing a damaged aortic valve through a small incision in the leg. A catheter is inserted into the femoral artery and guided up to the heart. The new valve is then positioned and deployed, restoring normal blood flow.

25 services25 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 93010

20 services20 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

20 services20 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.

20 services20 patients

Electrocardiogram (ecg) up to 30 days continuous with symptom monitoring, transmission and review and report by health care professional 93272

An Electrocardiogram (ECG) is a test that records the electrical activity of your heart. For up to 30 days, a device will continuously monitor your heart's rhythm, noting any symptoms. The data is sent to a healthcare professional who reviews it and provides a report on your heart health.

19 services19 patients

Ultrasound evaluation of heart blood vessel or graft with review by radiologist, initial vessel 92978

This procedure involves using ultrasound technology to examine the first vessel of your heart or graft. A radiologist will review the images. It's a non-invasive way to check the health of your heart's blood vessels.

16 services16 patients

New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more 99205

This is a first-time patient visit where a healthcare professional spends 60-74 minutes with you. It involves a comprehensive evaluation, including your medical history and current health condition. They'll also advise on preventive health measures and formulate a treatment plan if needed.

16 services16 patients

3d radiographic procedure 76376

A 3D radiographic procedure is a non-invasive imaging test that helps doctors visualize the internal structures of your body in three dimensions. This advanced technology provides detailed images, aiding in accurate diagnosis and treatment planning. It involves exposure to minimal radiation.

15 services14 patients

Insertion of tube in right and left heart chambers and coronary artery for diagnosis with review by radiologist 93460

This procedure involves placing a tube into the heart chambers and coronary artery. It helps diagnose heart conditions. A radiologist reviews the images obtained. It's a standard, safe procedure performed by experienced medical professionals.

13 services13 patients

Ultrasound evaluation of heart blood vessel during diagnosis or treatment, initial vessel 93571

This procedure involves using ultrasound technology to examine the first blood vessel of your heart. It helps identify any abnormalities or issues, providing crucial information for diagnosis or treatment. It's a safe, non-invasive process.

12 services12 patients

Hospital Affiliations CMS Care Compare 2

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

Lowell General Hospital

Acute Care Hospitals · Lowell, MA

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number220063

Location295 Varnum AvenueLowell, MA 01854 · Middlesex County

Emergency services Birthing friendly

Tufts Medical Center

Acute Care Hospitals · Boston, MA

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number220116

Location800 Washington StreetBoston, MA 02111 · Suffolk County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 01655 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

$73.22 typical visit price

range $19.11 – $144.84

Typical copayment $18.30 (range $4.77 – $36.21)

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.

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.

HILLARY R. IRONS MD

Emergency Medicine

55 LAKE AVE N
WORCESTER, MA 01655

Worcester County (508) 421-1400

MS. EILEEN A. DUHAMEL NP

Nurse Practitioner

55 LAKE AVE N, DEPARTMENT OF RADIOLOGY
WORCESTER, MA 01655

Worcester County (508) 334-2710

EWA HRYNISZYN CRNA

Nurse Anesthetist, Certified Registered

55 LAKE AVE N, DEPARTMENT OF ANESTHESIOLOGY
WORCESTER, MA 01655

Worcester County (508) 334-3271

HELEN COPSEY PA-C

Physician Assistant

55 LAKE AVE N
WORCESTER, MA 01655

Worcester County (508) 334-8585

DR. ADEPEJU GBADEBO CHAMPION M.D.

Internal Medicine

55 LAKE AVE N
WORCESTER, MA 01655

Worcester County (508) 334-2731

SOWMYA KORAPATI

Internal Medicine (Hematology & Oncology)

55 LAKE AVE N
WORCESTER, MA 01655

Worcester County (508) 334-3550

LAYLA FAKHRZADEH M.D.

Anesthesiology

55 LAKE AVE N, ANESTHESIOLOGY
WORCESTER, MA 01655

Worcester County (508) 334-3271

YOONYIE CHO M.D.

Anesthesiology

55 LAKE AVE N
WORCESTER, MA 01655

Worcester County (508) 334-1000

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 Nathan Riddell's NPI number?

The NPI number for Nathan Riddell is 1245670983. It was assigned to this individual provider in the NPPES registry on June 26, 2013.

Where is Nathan Riddell located?

Nathan Riddell practices at 55 Lake Ave N, Worcester, MA 01655. The listed phone number is (508) 334-1000.

What is Nathan Riddell's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Cardiovascular Disease, with taxonomy code 207RC0000X.

Is Nathan Riddell enrolled in Medicare?

Yes. Nathan Riddell 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 Nathan Riddell accept?

Health plans from Anthem Blue Cross and Blue Shield list Nathan Riddell 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 Nathan Riddell affiliated with any hospitals?

According to CMS data, Nathan Riddell is affiliated with Lowell General Hospital and Tufts Medical Center.

When was this NPI record last updated?

The NPPES record for Nathan Riddell was last updated on December 8, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 months 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.