Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Mark L Williams, MD

Individual provider Anesthesiology Physician · NPI 1679505440

Mark L Williams, MD practises Anesthesiology in Dallas, Texas. Qualified in 1986, 40 years ago. Practices with U S Anesthesia Partners of Texas, PA, a 2,747-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Arizona and Texas.

Years since qualifying
40
Licensed in
AZ, TX
In the registry since
2006
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

12222 Merit Dr Ste 600
Dallas, TX 75251-3294
Phone: (972) 715-5000
Fax: (972) 715-9976
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 250 E Dunlap Ave, Phoenix, AZ 85020 — (602) 273-9333

Specialties & licences

Anesthesiology Physician (primary) Taxonomy 207L00000X · Licence U4048 (TX)
Anesthesiology Physician Taxonomy 207L00000X · Licence 22063 (AZ)

Record details

NPI number1679505440
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 6, 2006
Last updated in NPPESApril 22, 2026
Certification dateApril 22, 2026

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyANESTHESIOLOGY
Medical schoolOTHER
Graduated 1986 (40 years in practice)
Group practice U S Anesthesia Partners Of Texas, Pa — 2747 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients119
Services billed 175 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Education $26 1 payment · educational material or training, not a fee
Food and Beverage $18 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

  • Methodist Richardson Medical Center Hospital · Richardson, TX · listed as Methodist Surgery Center - Richardson, LLC
  • Honor Health John C. Lincoln Medical Center Hospital · Phoenix, AZ

Colleagues at U S Anesthesia Partners of Texas, PA

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 2747 clinicians in the practice; 12 are shown here.

Other providers in Dallas