Thomas S Lam, M.D.
Gastroenterology Internal Medicine
Thomas S Lam is a Gastroenterology Internal Medicine specialist based in Alhambra, CA with over 45 years of clinical experience. Medicare-enrolled per CMS records and offers virtual telehealth visits.
Also practices: INTERNAL MEDICINE
Thomas S Lam, M.D. practices as part of a group gastroenterologist practice in Alhambra, CA. With 45+ years of experience, he has been practicing in the Alhambra area. CMS Medicare data shows his patients commonly have hypertension, high cholesterol, and diabetes.
At a glance
- Uses generic medications more than 54% of reporting doctors in California
- Virtual visits available — no app or travel required
Older · 340dNPPES updated 2025-06-17 · verify NPI on CMS · Verify license at Medical Board of California
Contact & Location
Practice Location
333 S Garfield Ave Ste a, Alhambra, CA 91801-3895
How Does This Doctor Compare?
Based on Medicare data, this doctor favors affordable generic drugs over brand-name ones.
Generic Rx
↑ Higher = better88.4%
California avg: 83.3 · US avg: 82.8
✓ Higher than most doctors nationally(+5.6 pts)
Typical range among reporting doctors in CaliforniaHow often this doctor prescribes affordable generic drugs instead of expensive brand-name ones.
Medicare Patients
125
Unique beneficiaries
Standard volumePrescription Recipients
166
Patients prescribed
Prescriptions Written
372
Total claims
Total Medicare drug cost: $41k
Percentile rankings compared against 9,360 reporting peers in California.
Data Note: Sourced from CMS Medicare Provider Utilization & Payment Data. Percentile rankings compare this provider against all peers with reported data in the same state. Updated annually to reflect the latest federal reporting cycle.
What This Doctor Treats Most
Based on Medicare claims data — here's what patients commonly see this doctor for
Based on Medicare data, this doctor primarily manages Hypertension, High Cholesterol, and Diabetes.
High blood pressure — a leading risk factor for heart disease and stroke
US avg: 70.2%↑ More patients than average (+5%) — a focus area for this doctor
Elevated cholesterol or triglycerides that increase heart disease risk
US avg: 70.4%↑ More patients than average (+5%) — a focus area for this doctor
A condition where the body cannot properly regulate blood sugar levels
US avg: 34.5%↑ More patients than average (+18%) — a focus area for this doctor
Joint inflammation causing pain, swelling, and stiffness
US avg: 49.3%↓ Fewer patients than average (-8%) — less common here
Gradual loss of kidney function over time, often linked to diabetes or hypertension
US avg: 29.6%↑ More patients than average (+8%) — a focus area for this doctor
Weakened bones that are more prone to fractures, common in older adults
US avg: 18.1%↑ More patients than average (+18%) — a focus area for this doctor
Reduced blood flow to the heart muscle, commonly known as coronary artery disease
US avg: 31.7%↓ Fewer patients than average (-2%) — less common here
Percentage of this provider's Medicare patients diagnosed with each condition. Source: CMS Utilization Data.
$340 received from industry
14 transactions reported in 2018 ·Low tier
Payments include consulting fees, speaking honoraria, food & beverage, travel, research support, and ownership interests from drug and medical device manufacturers. Disclosure is required by the federal Physician Payments Sunshine Act. These payments do not necessarily indicate conflicts of interest. National median: $338 across 136 000 tracked providers.
Tiers — Low: under $500 · Moderate: $500-5 000 · High: $5 000-25 000 · Very High: $25 000+. Source: CMS Open Payments 2018, attributed to Thomas S Lam's NPI.
Patient Reviews
No patient reviews yet. If you've seen Thomas S Lam, your feedback helps other patients.
Review PolicyAll feedback is moderated before publishing. We verify reviewer identity where possible and enforce a one-review-per-provider policy. Full guidelines →
Background & Specialty
Education, training, and specialty classification from CMS NPPES and Medicare records.
Board certified · Jun 16, 2025
Self-reported via NPPES
45 years in practice
Senior practitioner
Gastroenterologists diagnose and treat digestive system disorders including GERD, irritable bowel syndrome (IBS), inflammatory bowel disease (Crohn's, ulcerative colitis), liver disease, pancreatitis, and colon polyps. They perform endoscopies and colonoscopies.
Taxonomy: 207RG0100X
Mailing address
Po Box 7589, Alhambra, CA 91802-7589
Differs from practice location
Virtual Internal Medicine Care With Thomas S Lam
NPPES records indicate this provider offers telehealth services. Contact the office to confirm availability and scheduling.
Schedule a virtual visit with Thomas S Lam for blood pressure monitoring, cholesterol management, diabetes check-ins — no travel to Alhambra required. The office sends a secure video link before your appointment. Most visits take 15–30 minutes. Medicare enrolled per CMS records.
Frequently Asked Questions
Common questions about Thomas S Lam
Dr. Lam is listed as active in the NPI registry with telehealth listed in Alhambra, CA. NPI status alone doesn't confirm open availability — call the office to confirm. Phone: (626) 284-1997.
Sourced from CMS NPPES · OIG LEIE · CMS Medicare Part D · CMS Open Payments 2018 · CMS Physician Comparator. See Data Methodology.
Is this your profile?
Verify credentials, update practice details, and manage telehealth.
Medical Disclaimer: NPI Telehealth is a provider directory for informational purposes only. This page does not constitute medical advice, diagnosis, or treatment recommendations. Provider data is sourced from the CMS NPPES federal registry and public Medicare datasets. NPI Telehealth does not verify clinical qualifications beyond federal records. Data may not reflect real-time availability — always contact the provider's office directly to confirm details before seeking care.
Contact Thomas S Lam
Practice Location
333 S Garfield Ave Ste a, Alhambra, CA 91801-3895
Mailing Address
Po Box 7589, Alhambra, CA 91802-7589
This is a provider directory. Contact the office directly to schedule appointments.
Related Providers
Gastroenterology Internal Medicine in California
See allGerson Charles Bernhard, MD
San Francisco, CA
John P. Kane, MD
San Francisco, CA
Yzhar Charuzi, M.D
Los Angeles, CA