DR. MARK WILLIAMS MD
NPI 1770558702
Internal Medicine - Nephrology in Winter Park, FL

Q: What is Mark Williams's NPI number?

The NPI number for Mark Williams is 1770558702. It was assigned to this individual provider in the NPPES registry on February 22, 2006.

Q: What is Mark Williams's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Nephrology, with taxonomy code 207RN0300X.

Q: When was this NPI record last updated?

The NPPES record for Mark Williams was last updated on November 7, 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.

Active since February 22, 2006PECOS Enrolled

3727 N GOLDENROD RD STE 105, WINTER PARK, FL 32792(407) 657-0296 Get Directions Write a Review

NPPES record last updated: November 7, 2022. Verified against the NPPES registry weekly; last sync: October 25, 2026.

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About Dr. Mark Williams Md NPPES

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

DR. MARK WILLIAMS MD (NPI 1770558702) is an individual nephrology provider in Winter Park, Florida, licensed in Florida (ME54570) and active in the NPI registry since February 2006. He is enrolled in Medicare PECOS and maintains a secondary practice location in Orlando.

NPPES Registry Identity

NPI1770558702

Entity TypeIndividualMale

Primary Taxonomy207RN0300X

Provider Legal NameDR. MARK WILLIAMSCredential: MD

Location Address3727 N GOLDENROD RD STE 105Winter Park, FL 32792-8611

Mailing Address3885 Oakwater CirOrlando, FL 32806-6257 · (407) 816-5700 · Fax (407) 812-6766

Phone(407) 657-0296

Sole ProprietorNo

Enumeration DateFebruary 22, 2006

Last NPPES UpdateNovember 7, 2022

NPPES CertifiedNovember 7, 2022

✔ NPI 1770558702 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · NephrologyAllopathic & Osteopathic Physicians

Taxonomy Code207RN0300X

License✔ Licensed in FL · ME54570

Definition

An internist who treats disorders of the kidney, high blood pressure, fluid and mineral balance and dialysis of body wastes when the kidneys do not function. This specialist consults with surgeons about kidney transplantation.

3727 N GOLDENROD RD STE 105, Winter Park, FL 32792

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Secondary Practice Location 1

Location 13885 Oakwater CirOrlando, FL 32806-6257 · Phone (407) 816-5700 · Fax (407) 812-6766

Other Identifiers 4

Other0624921FL · Aetna

Medicaid061510200FL

Other08545FL · Bc/bs

Other3100042FL · United Healthcare

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Mark Williams 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

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

Central Florida Kidney Specialists Inc

8.5 mi

Nephrology

3885 OAKWATER CIR
Orlando, FL 32806

Reassigned Medicare billing, Florida enrollment
49 clinicians in this Medicare group

NPI 1346954138 (407) 816-5700

Nephrology Associates Of Central Florida, P.A.

9.1 mi

Nephrology

2180 W SR 434 STE 1164
Longwood, FL 32779

Reassigned Medicare billing, Florida enrollment
70 clinicians in this Medicare group

NPI 1346297173 (407) 894-4693

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 32792 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

$130.04 typical visit price

range $56.00 – $171.84

Typical copayment $32.51 (range $14.00 – $42.96)

Most-billed visit code 99204

Established Patient

$99.16 typical visit price

range $17.57 – $139.16

Typical copayment $24.79 (range $4.39 – $34.79)

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.

Referred Medical Equipment & Supplies CMS DME claims 3

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Tacrolimus, immediate release, oral, 1 mg J7507

Treatment-Treatment - Miscellaneous · category RX029N

2 suppliers22 claims2,070 services$0.30 avg. paid by Medicare

Mycophenolic acid, oral, 180 mg J7518

Treatment-Treatment - Miscellaneous · category RX029N

1 supplier14 claims2,400 services$0.95 avg. paid by Medicare

Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for a subsequent prescription in a 30-day period Q0512

Treatment-Chemotherapy · category RH012N

3 suppliers23 claims25 services$12.64 avg. paid by Medicare

Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES

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

DR. CHIDAMBARAM SUNDER VALLIAPPAN M.D.

Internal Medicine (Nephrology)

3727 N GOLDENROD RD STE 105
WINTER PARK, FL 32792

Orange County (407) 657-0296

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 Mark Williams's NPI number?

The NPI number for Mark Williams is 1770558702. It was assigned to this individual provider in the NPPES registry on February 22, 2006.

Where is Mark Williams located?

Mark Williams practices at 3727 N Goldenrod Rd Ste 105, Winter Park, FL 32792. The listed phone number is (407) 657-0296.

What is Mark Williams's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Nephrology, with taxonomy code 207RN0300X.

Is Mark Williams enrolled in Medicare?

Yes. Mark Williams is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Mark Williams's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mark Williams reassigns Medicare benefits to 2 organizations: Central Florida Kidney Specialists Inc (Orlando, FL) and Nephrology Associates Of Central Florida, P.A. (Longwood, FL). 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 Mark Williams's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Mark Williams was last updated on November 7, 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.