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DR. WILLIAM W ONEILL MD
NPI 1881676435
Internal Medicine - Cardiovascular Disease in Naples, FL

Active since November 18, 2005PECOS Enrolled
399 9TH ST N STE 300, NAPLES, FL 34102(239) 624-4299(239) 624-8856 Get Directions Write a Review

NPPES record last updated: April 18, 2025. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Dr. William W Oneill Md NPPES

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

DR. WILLIAM W ONEILL MD (NPI 1881676435) is an individual cardiovascular disease provider in Naples, Florida, licensed in Florida (ME173217) and active in the NPI registry since November 2005. He is enrolled in Medicare PECOS and maintains a secondary practice location in Detroit.

NPPES Registry Identity

NPI1881676435
Entity TypeIndividualMale
Primary Taxonomy207RC0000X
Provider Legal NameDR. WILLIAM W ONEILLCredential: MD
Location Address399 9TH ST N STE 300Naples, FL 34102-5820
Mailing Address2799 W Grand Blvd, K14 Office B1417Detroit, MI 48202-2608 · (313) 916-1878 · Fax (313) 916-2819
Phone(239) 624-4299
Fax(239) 624-8856
Sole ProprietorYes
Enumeration DateNovember 18, 2005
Last NPPES UpdateApril 18, 2025
NPPES CertifiedApril 18, 2025
✔ NPI 1881676435 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Cardiovascular DiseaseAllopathic & Osteopathic Physicians
Taxonomy Code207RC0000X
Licenses✔ Licensed in FL · ME173217✔ Licensed in MI · 4301039889
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 Medicine · Interventional CardiologyTaxonomy 207RI0011X · License ME0097328 (FL), 4301039889 (MI)
399 9TH ST N STE 300, Naples, FL 34102
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Secondary Practice Location 1

Location 12799 W Grand Blvd, K14 Office B1417Detroit, MI 48202-2608 · Phone (313) 916-1878 · Fax (313) 916-2819

Other Identifiers 2

Medicaid2772965-00FL
OtherAA352XFL · Medicare Id-type Unspecified

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Buckeye Health Plan, Ambetter from Meridian, Ambetter Health.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. William W Oneill Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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

2

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

W.A. Foote Memorial Hospital
1,118 mi
Physician Assistant
205 N. EAST AVE
Jackson, MI 49201
  • Reassigned Medicare billing, Michigan enrollment
  • 225 clinicians in this Medicare group
NPI 1235676180 (517) 841-7843
Henry Ford Health System
1,120 mi
Plastic Surgery
2799 W GRAND BLVD
Detroit, MI 48202
  • Reassigned Medicare billing, Michigan enrollment
  • 1,886 clinicians in this Medicare group
NPI 1528142858 (313) 916-2600

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 3

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.

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.
16 services16 patients
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.
13 services13 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.
13 services13 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 34102 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
$135.56 typical visit price
range $58.56 – $179.05
Typical copayment $33.89 (range $14.64 – $44.76)
Most-billed visit code 99204
Established Patient
$73.00 typical visit price
range $18.44 – $144.68
Typical copayment $18.25 (range $4.61 – $36.17)
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.

JULIANA MADISON APRN
Nurse Practitioner (Family)
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200
CARL EDWARD ORRINGER MD
Internal Medicine (Cardiovascular Disease)
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200
SUZANNE M HILTZ PA-C
Physician Assistant
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200
HANY MEDHAT BADIE MOHAMED ELMAHDY M.D.
Internal Medicine (Cardiovascular Disease)
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200
LORI KATAWCZIK PA
Physician Assistant
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4299
DR. HERMAN L. SPILKER M.D.
Internal Medicine (Cardiovascular Disease)
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200
SANDRA J KREUL ARNP
Nurse Practitioner
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200
GEORGE EDWARD FERNANDEZ
Nurse Practitioner (Adult Health)
399 9TH ST N STE 300
NAPLES, FL 34102
Collier County (239) 624-4200

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 William Oneill's NPI number?

The NPI number for William Oneill is 1881676435. It was assigned to this individual provider in the NPPES registry on November 18, 2005.

Where is William Oneill located?

William Oneill practices at 399 9th St N Ste 300, Naples, FL 34102. The listed phone number is (239) 624-4299.

What is William Oneill's specialty?

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

Is William Oneill enrolled in Medicare?

Yes. William Oneill is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for William Oneill's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Oneill reassigns Medicare benefits to 2 organizations: W.A. Foote Memorial Hospital (Jackson, MI) and Henry Ford Health System (Detroit, MI). 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 William Oneill's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does William Oneill accept?

Health plans from Ambetter Health, Ambetter from Buckeye Health Plan and Ambetter from Meridian list William Oneill 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.

When was this NPI record last updated?

The NPPES record for William Oneill was last updated on April 18, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.