Skip to main content

Dr. Iris Ma

Internal Medicine (Internal Medicine Physician)

300 Pasteur Dr
Stanford, CA 94305

Who else practices at this address →

Santa Clara County includes mental health (13% of residents) shortage areas. About shortage areas

Call (650) 723-4000

  • Medicare participating

At a glance

Years since graduation
16
In the NPI registry since
2011
Medicare patients seen, 2024
240

Licensed in California since 2012, according to the Medical Board of California. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.

The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. What an NPI is

Education and training

  • 2010Medical school: University of California, San Francisco School of Medicine
  • 2011Registered with an NPI (national billing number; not a license date)

Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).

Specialties and state licenses

  • Internal Medicine Physician primary
    CA license A122086 (first issued 2012; current)

As reported to the NPI registry. To confirm a license is current, check the state medical board.

Map: Internal Medicine per capita by county →

Where they work

Hospitals

Medical groups

Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.

Medicare patients and services

Medicare patients, 2024
240
Services billed
772
Patients’ average age
76
Most frequent Medicare services, 2023
ServiceTimesPatients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes603212
Hospital discharge day management, more than 30 minutes141139
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes7978
Physician or allowed practitioner certification for medicare-covered home health services under a home health plan of care (patient not present), including contacts with home health agency and review of reports of patient status required by physicians and5550
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes4419
Critical care, first 30-74 minutes3318

Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.

Medicare prescriptions

Most prescribed drugs, Medicare Part D 2024
DrugPrescriptions
Eliquis (apixaban)
Other prescribers in Stanford, CA
14

Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.

Other Internal Medicine clinicians in Stanford

Sources

NPI registry (CMS NPPES, November 2026; record last updated September 20, 2016), Medicare Care Compare, Medicare Physician & Other Practitioners (2024), Medicare Part D Prescribers (2024) and Open Payments (2025). Information is self-reported or billed data and may be out of date; call before visiting.

NPI 1598055766. Official NPI registry record (opens in a new tab). Clinicians can correct their information in NPPES; changes appear here after our next monthly update.