Quick answers
- Does Andrea S. Tieng accept Medicare assignment?
- Yes. Medicare's clinician data says Andrea S. Tieng accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Andrea S. Tieng see?
- In 2024, CMS data shows 98 Original Medicare patients and 164 services for Andrea S. Tieng. This counts Original Medicare only and measures volume, not quality.
- What is Andrea S. Tieng's NPI number?
- 1356528566. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Andrea S. Tieng, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 98 |
|---|---|
| Services billed to Medicare | 164 |
| Different services or procedures | 10 |
| Participating Medicare provider | Yes |
| Average age of these patients | 71 |
Most frequent services
- Removal of polyps or growths of large bowel using an endoscope with mechanical snare (45385)33 services
- Moderate sedation services provided by the same physician or other qualified health care professional performing a gastrointestinal endoscopic service that sedation supports, requiring the presence of an independent trained observer to assist in the monito (G0500)32 services
- Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43239)22 services
- New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more (99203)22 services
- Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk (G0121)17 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol73%
- High blood pressure67%
- Arthritis53%
- Diabetes42%
- Anxiety18%
- Osteoporosis17%
Hospitals where Andrea S. Tieng works
Medicare's Facility Affiliation Data lists Andrea S. Tieng at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- San Antonio Regional HospitalUpland, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050099
Practice locations
Addresses where Andrea S. Tieng is enrolled with Medicare (CMS data updated October 2, 2026).
- 10408 Industrial CirRedlands, CA 92374 (909) 796‑7803
- 10801 Foothill Blvd, Suite 106Rancho Cucamonga, CA 91730 (909) 255‑7200
Specialties
- Gastroenterologyprimary
Other gastroenterologists in Redlands
Clinicians with the same Medicare primary specialty in Redlands, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2003 (23 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1356528566 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians