Doctor profile · Federal record

Dr. Mark Williams, PHD

Clinical Psychologist · Altamonte Springs, FL

  • NPI 1619998416
  • MIPS 100.0 / 100 · 2023
  • 20 yrs on file
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
989 Orienta Ave, Life Care Center of Altamonte
Altamonte Springs, FL 32701
(407) 831-3446
Mailing address
3851 Ethan Lane
Orlando, FL 328146567

Credentials & registration

NPPES · NUCC
NPI registered
July 2006 — 20 yrs on file
Profile last updated
July 8, 2007
Specialty taxonomy
103TC0700X — NUCC code
State license (1)
Florida #PY0003957

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1619998416. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
126
Distinct HCPCS
2
Medicare allowed
$14,586
HCPCS Description Services Patients Avg allowed
90791 Psychiatric diagnostic evaluation 79 79 $146
90832 Psychotherapy, 30 minutes 47 38 $64

In context: peer comparison

Among 1 peers in Altamonte Springs Clinical Psychologist, average services per provider: 63. This provider delivers 2.0× the peer median.

Frequently asked questions

Auto-generated from federal data
What is Dr. Mark Williams's medical specialty?
Dr. Mark Williams practices Clinical Psychologist in Altamonte Springs, FL.
Where does Dr. Mark Williams practice?
Dr. Mark Williams practices at 989 Orienta Ave, Altamonte Springs, FL 32701. Office phone: 4078313446.
What is Dr. Mark Williams's NPI?
Dr. Mark Williams's National Provider Identifier (NPI) is 1619998416, issued by NPPES.
What procedures does Dr. Mark Williams commonly perform?
Top Medicare-reported procedures in 2023: Psychiatric diagnostic evaluation (HCPCS 90791); Psychotherapy (HCPCS 90832). Source: CMS Medicare Physician & Other Practitioners file.