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Active NPI 1245641869 Individual Practitioner Male Practitioner

Dr. Andrew Richard Williams , MD

Internal Medicine • Pasadena, CA

✓ Accepts Medicare Assignment
Public Directory Information & Medical Disclaimer

This profile is compiled from official public domain records provided by CMS and the NPPES registry. TRUE-MEDINFO is an independent reference directory and does not provide medical advice, diagnosis, or treatment recommendations. Always consult a licensed medical professional for personal health decisions.

Professional Overview & Biography Verified Profile Summary

Dr. Andrew Williams, MD is a registered Internal Medicine practitioner in Pasadena, CA. With approximately 13 years of clinical practice since completing medical education in 2013, Dr. Williams provides healthcare services at the registered practice location at 100 W CALIFORNIA BLVD.

Dr. Williams is affiliated with Healthcare Partners Affiliates Medical Group and accepts Medicare assignment.

Frequently performed procedures and clinical services include subsequent hospital care with moderate levelof medical decision making, if using time, at least, hospital discharge day management, more than, initial hospital care with straightforward or low-level medical decision making, if using time, at least. Full Medicare procedure pricing transparency rates and service volume details are listed on this profile.

Practice Location & Contact Primary Location

Practice Address

100 W California Blvd

Pasadena, CA 911053010

Telephone 6263975000
Associated Practice Facility / Clinic
🏢 The Hill Medical Corporation Facility NPI 1154310415

Medicare Profile & Education

Medical School

Other

Graduation Year

2013

Medicare Assignment

✓ Accepts Assignment

Telehealth Flag

In-Person Only

Specialty Benchmarks & Practice Insights

Comparative analytics for Internal Medicine in Pasadena, CA

Established Specialist (10-20 Yrs)
Practitioner Clinical Experience
13 Yrs -11.3 yrs vs City Avg
City Avg: 24.3 Yrs
State Avg: 26.6 Yrs
Regional Practice Density
149 Specialists

Practicing in Pasadena, CA (18502 Statewide)

Telehealth Adoption Rate
32.2% Regional Adoption

In-Person Office Visits Only

Medicare Pricing Discount
38.3% Avg Savings

Under CMS Medicare Fee Schedule vs Standard Submitted Charges

Clinical Seniority & Experience Comparison

Dr. Williams (13 Years) 13 Yrs
Pasadena Specialty Average (24.3 Years) 24.3 Yrs

Performed Procedures & Service Volume

Top Medicare Part B procedures performed by this practitioner

CMS Official Data (2022)
Reporting Year:
HCPCS Code & Description Services Patients Submitted Charge Medicare Allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes
55 18 $170.00 $104.91

Medical Specialties & State Licenses

CMS Verified: 2026-01-15
Internal Medicine Primary Specialty

NUCC Taxonomy Code: 207R00000X

State License CA A135707

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

Hospital & Practice Group Affiliations

Healthcare Partners Affiliates Medical Group

301 S Fair Oaks Ave, Pasadena, CA 911052562

Phone: 6268213530

Practice Associates & Co-Workers

Healthcare professionals and specialists practicing at this location or sharing practice phone/fax

40 Associated Practitioners
Dr. Paul Lee , MD

Internal Medicine

NPI 1023561172

Doctor of Medicine (M.D.)

Camille Medina

Nurse Practitioner - Psychiatric/Mental Health

NPI 1033901582
Dr. Johnathan Chou , MD

Student in an Organized Health Care Education/Training Program

NPI 1043621691

Doctor of Medicine (M.D.)

Dr. Jonwei Hwang , MD

Student in an Organized Health Care Education/Training Program

NPI 1053044271

Doctor of Medicine (M.D.)

Jeffrey Robeff , RN

Registered Nurse - Psychiatric/Mental Health, Adult

NPI 1053965087

Registered Nurse

Dr. Chelsea Lam , MD

Student in an Organized Health Care Education/Training Program

NPI 1073121786

Doctor of Medicine (M.D.)

Career & Practice History Timeline

Chronological log of verified NPI updates, location relocations, credentials, and registry changes

8 Historical Events
📍
Updated Business Mailing Address January 15, 2026

Registered at PO BOX 35380, LAS VEGAS, NV 891335380 (Tel: 7025793203)

🎓
Medical Taxonomy / Specialty Registered (Primary Specialty) July 02, 2025

Internal Medicine (License #A135707 in CA)

NPI Profile Active May 16, 2014

NPI status registered as active in NPPES database

📍
Updated Practice Location May 16, 2014

Registered at 100 W CALIFORNIA BLVD, PASADENA, CA 911053010 (Tel: 6263975000)

📍
Updated Business Mailing Address May 16, 2014

Registered at 1616 DELTA ST, #101, LOS ANGELES, CA 900262678 (Tel: 4088023538)

👤
Provider Name / Credentials Updated May 16, 2014

Recorded as ANDREW WILLIAMS, M.D.

🎓
Medical Taxonomy / Specialty Registered (Primary Specialty) May 16, 2014

Student in an Organized Health Care Education/Training Program

🟢
Initial NPI Registration & Enumeration May 16, 2014

First registered as active Individual Practitioner in NPPES Database.

Patient & Community Reviews

Verified patient ratings, medical care experiences, and facility photos

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NPI Administrative Meta

NPI Number: 1245641869
Entity Type:
Individual Provider Physician, Nurse Practitioner, or Solo Healthcare Professional (Type 1 NPI)
Enumeration Date: May 16, 2014
Last Update: January 15, 2026
Sole Proprietor: No

Mailing Address

Po Box 35380

Las Vegas, NV 891335380

Phone: 7025793203

Public Domain Record This profile contains public domain information published by CMS and NPPES under the Freedom of Information Act (FOIA).
⚠️ Medical Disclaimer

This directory listing is for informational purposes only and does not constitute medical advice, diagnosis, or physician endorsement. If you are experiencing a medical emergency, please call 911 immediately.