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DENISE I. FITZSIMON MD
NPI 1861525636
Pediatrics in Round Rock, TX

Active since March 13, 2007PECOS Enrolled
300 UNIVERSITY BLVD, ROUND ROCK, TX 78665(512) 509-0200 Get Directions Write a Review

NPPES record last updated: November 9, 2022. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Denise I. Fitzsimon Md NPPES

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

DENISE I. FITZSIMON MD (NPI 1861525636) is an individual pediatrics provider in Round Rock, Texas, licensed in Texas (H1960) and active in the NPI registry since March 2007. She is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1861525636
Entity TypeIndividualFemale
Primary Taxonomy208000000X
Provider Legal NameDENISE I. FITZSIMONCredential: MD
Location Address300 UNIVERSITY BLVDRound Rock, TX 78665-1032
Mailing AddressPo Box 844658Dallas, TX 75284-4658
Phone(512) 509-0200
Sole ProprietorNo
Enumeration DateMarch 13, 2007
Last NPPES UpdateNovember 9, 2022
NPPES CertifiedNovember 9, 2022
✔ NPI 1861525636 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPediatricsAllopathic & Osteopathic Physicians
Taxonomy Code208000000X
Licenses✔ Licensed in TX · H1960✔ Licensed in AK · 3954✔ Licensed in OR · MD26536✔ Licensed in WA · MD00046928
Definition
A pediatrician is concerned with the physical, emotional and social health of children from birth to young adulthood. Care encompasses a broad spectrum of health services ranging from preventive healthcare to the diagnosis and treatment of acute and chronic diseases. A pediatrician deals with biological, social and environmental influences on the developing child, and with the impact of disease and dysfunction on development.
300 UNIVERSITY BLVD, Round Rock, TX 78665
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Other Names 1

Former Name (1)Denise I. Fitzsimon-williams Md

Other Identifiers 2

Medicaid278407OR
Medicaid218112OR

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include PacificSource Health Plans.Insurance ›

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Denise I. Fitzsimon 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

4

Medicare enrollment records show Denise Fitzsimon reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Saint Alphonsus Medical Center- Ontario Inc
1,405 mi
Emergency Medicine
351 SW 9TH ST
Ontario, OR 97914
  • Reassigned Medicare billing, Oregon enrollment
  • 49 clinicians in this Medicare group
NPI 1275852337 (541) 881-7000
St Anthony Hospital
1,542 mi
Pediatrics
1514 SE COURT AVE
Pendleton, OR 97801
  • Reassigned Medicare billing, Oregon enrollment
  • 34 clinicians in this Medicare group
NPI 1740411800 (541) 276-5121
Siskiyou Hospital, Inc.
1,585 mi
Critical Access
444 BRUCE ST
Yreka, CA 96097
  • Reassigned Medicare billing, California enrollment
  • 140 clinicians in this Medicare group
NPI 1093892275 (530) 842-4121
Northwest Medical Foundation Of Tillamook
1,661 mi
Rural Health
24461 E WELCHES RD
Welches, OR 97067
  • Reassigned Medicare billing, Oregon enrollment
  • 206 clinicians in this Medicare group
NPI 1861944894 (503) 842-4444

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 78665 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
$84.92 typical visit price
range $54.84 – $166.88
Typical copayment $21.23 (range $13.71 – $41.72)
Most-billed visit code 99203
Established Patient
$97.05 typical visit price
range $17.52 – $136.11
Typical copayment $24.26 (range $4.38 – $34.02)
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 20

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

BRENNEN J. BEATTY MD
Emergency Medicine
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
KATHLEEN SUSAN GRADY-GREENE ARNP
Nurse Practitioner (Neonatal)
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0200
MATTHEW RYAN DANLEY D.O.
Anesthesiology
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
CODY R. QUIRK M.D.
Radiology (Diagnostic Radiology)
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
CAITLIN O'CONNOR CRNA
Nurse Anesthetist, Certified Registered
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
MARCEL ALBERT GRAF AA-C
Anesthesiologist Assistant
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0200
SADIE JOHNSON RN
Registered Nurse
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (940) 595-0169
DR. JACLYN NGOC MINH NGUYEN MD
Emergency Medicine
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100

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 Denise Fitzsimon's NPI number?

The NPI number for Denise Fitzsimon is 1861525636. It was assigned to this individual provider in the NPPES registry on March 13, 2007. The provider is also known as Denise I. Fitzsimon-Williams MD.

Where is Denise Fitzsimon located?

Denise Fitzsimon practices at 300 University Blvd, Round Rock, TX 78665. The listed phone number is (512) 509-0200.

What is Denise Fitzsimon's specialty?

The primary specialty registered for this NPI is Pediatrics with taxonomy code 208000000X.

Is Denise Fitzsimon enrolled in Medicare?

Yes. Denise Fitzsimon is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Denise Fitzsimon's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Denise Fitzsimon reassigns Medicare benefits to 4 organizations: Saint Alphonsus Medical Center- Ontario Inc (Ontario, OR), St Anthony Hospital (Pendleton, OR), Siskiyou Hospital, Inc. (Yreka, CA) and Northwest Medical Foundation Of Tillamook (Welches, OR). 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 Denise Fitzsimon's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Denise Fitzsimon accept?

Health plans from PacificSource Health Plans list Denise Fitzsimon 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 Denise Fitzsimon was last updated on November 9, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.