James Dale Williamson Jr., PA-C

James Williamson practices at Dignity Health - Mercy Medical Center in Merced, California, part of CommonSpirit Health.

James Williamson's NPI, 1306072046, was assigned on June 9, 2009.

James Williamson's primary practice is Dignity Health - Mercy Medical Center, at 333 Mercy Avenue, Merced, CA 95340 in Merced County. The practice phone is (209) 564-5000.

James Williamson's primary practice is Dignity Health - Mercy Medical Center in Merced, California, part of CommonSpirit Health. The medical group on file is San Joaquin Emergency Medical Associates. Dmand AI also links James Williamson to 1 more hospital outpatient department and 1 rural health clinic, each named with a free account.

Dmand AI tracks the electronic health record (EHR) system at each site where James Williamson practices, 3 sites in all. Vendor and product names are available with a free account.

Medical is James Williamson's primary specialty in the NPI Registry, under taxonomy code 363AM0700X. James Williamson is board certified in certified physician assistant by the National Commission on Certification of Physician Assistants (NCCPA).

CMS data shows 125 Medicare services from James Williamson across 2 procedure codes in 2024, for 127 Medicare patients. Medicare paid $10,401 for them. Every service was in a facility, such as a hospital, rather than an office.

CMS counts 127 Medicare patients who saw James Williamson in 2024. The largest group is 65 to 74, with 52 patients. 67% of them have high cholesterol, and 66% have high blood pressure. 68% are also on Medicaid. Their average risk score is 1.38, where 1.00 is the Medicare average.

Across all payers, Dmand AI patient panel data puts James Williamson's median patient age at 63, with 52% women.

In 2024, James Williamson wrote 6,293 Medicare Part D claims for 432 patients. 87% of them were for generic drugs. CMS names the drug for 5,592 of them, across 123 drugs with 11 or more claims each, at $883,231 in total drug cost.

CMS Open Payments shows 88 general payments to James Williamson from 6 drug and device companies from 2024 to 2025. Food and beverage make up the largest share, 99% of the total. Corcept Therapeutics paid the most, $1,099.

James Williamson is a member of AAPA.