1. Home
  2. Directory
  3. Florida
  4. Hialeah
  5. Internal Medicine
  6. NPI Profile

GRISEL MAC WILLIAMS MD PA
NPI 1083910202
Internal Medicine in Hialeah, FL

Active since February 05, 2011CLIA 10D2063191 · Waiver
810 E 39TH PL, HIALEAH, FL 33013(305) 691-7018(305) 691-5814 Get Directions Write a Review

NPPES record last updated: April 2, 2024. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Apr 2, 2024, Jan 6, 2021, May 20, 2020 (3 updates tracked since 2020).

About Grisel Mac Williams Md Pa NPPES

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

GRISEL MAC WILLIAMS MD PA (NPI 1083910202) is a healthcare organization registered as an internal medicine in Hialeah, Florida and active in the NPI registry since February 2011. The organization holds a CLIA Waiver certificate valid through July 28, 2027, maintains a secondary practice location in Pembroke Pines, and lists Michel Diaz, Office Manager, as its authorized official.

NPPES Registry Identity

NPI1083910202
Entity TypeOrganization
Primary Taxonomy207R00000X
Legal Business NameGRISEL MAC WILLIAMS MD PA
Location Address810 E 39TH PLHialeah, FL 33013-2863
Mailing Address810 E 39th PlHialeah, FL 33013-2863 · (305) 691-7018 · Fax (305) 691-5814
Phone(305) 691-7018
Fax(305) 691-5814
Organization SubpartNo
Authorized OfficialMichel DiazOffice Manager · (305) 691-7018
Enumeration DateFebruary 5, 2011
Last NPPES UpdateApril 2, 20243 updates tracked since enumeration
NPPES CertifiedApril 2, 2024
✔ NPI 1083910202 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
810 E 39TH PL, Hialeah, FL 33013
Open in Google Maps ↗

Secondary Practice Location 1

Location 118044 NW 6th St Ste 101Pembroke Pines, FL 33029-2824 · Phone (954) 885-9904

Other Identifiers 1

Medicaid047895400FL

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include AvMed.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Grisel Mac Williams Md Pa is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

2

Medicare enrollment records show 2 clinicians reassign Medicare billing to Grisel Mac Williams MD PA, which bills Medicare for the services they deliver. Of these, 1 practice at this address. They are listed nearest first.

Clinicians, nearest first (2)

Grisel Mac Williams, MD
Internal Medicine
NPI 1053396549
810 E 39TH PL
Hialeah, FL 33013
(305) 691-7018
✔ PECOS✔ Accepts MedicareSame address
Natasha Morejon, ARNP
Nurse Practitioner
NPI 1083094700
1968 NW 166TH AVE
Pembroke Pines, FL 33028
(754) 244-9702
✔ PECOS13 mi

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

CLIA Laboratory Certificates CMS CLIA

Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.

Certificate of Waiver 10D2063191

Grisel Mac Williams MD PA · Pembroke Pines, FL
Active · expires Jul 28, 2027
CLIA Number10D2063191
Laboratory TypePhysician Office
Certificate Effective DateJuly 29, 2025
Certificate Expiration DateJuly 28, 2027
Laboratory DirectorGrisel M. Willams
Laboratory Phone(954) 885-9904
Laboratory LocationGrisel Mac Williams MD PA18044 NW 6th St Ste 102, Pembroke Pines, FL 33029
CLIA data matches this NPI record on: Name Phone
This certificate is issued to a laboratory to perform only waived tests.

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 Grisel Mac Williams MD PA's NPI number?

The NPI number for Grisel Mac Williams MD PA is 1083910202. It was assigned to this organization in the NPPES registry on February 5, 2011.

Where is Grisel Mac Williams MD PA located?

Grisel Mac Williams MD PA is located at 810 E 39th Pl, Hialeah, FL 33013. The listed phone number is (305) 691-7018.

What is Grisel Mac Williams MD PA's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Grisel Mac Williams MD PA enrolled in Medicare?

Yes. Grisel Mac Williams MD PA is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Grisel Mac Williams MD PA?

According to the CMS Revalidation Reassignment List (October 2026 release), 2 clinicians reassign their Medicare billing to Grisel Mac Williams MD PA, in Internal Medicine and Nurse Practitioner. A 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 the clinician's services. Of these, 1 practice at this address. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does Grisel Mac Williams MD PA hold a CLIA laboratory certificate?

Yes. A Certificate of Waiver (number 10D2063191) is associated with this NPI, valid through July 28, 2027. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

What insurance does Grisel Mac Williams MD PA accept?

Health plans from AvMed list Grisel Mac Williams MD PA 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 Grisel Mac Williams MD PA was last updated on April 2, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.