Quick answers
- Does Maria G. Tan accept Medicare assignment?
- Medicare's clinician data says Maria G. Tan may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- How many Medicare patients does Maria G. Tan see?
- In 2024, CMS data shows 25 Original Medicare patients and 124 services for Maria G. Tan. This counts Original Medicare only and measures volume, not quality.
- What is Maria G. Tan's NPI number?
- 1689666158. 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 Maria G. Tan, 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 | 25 |
|---|---|
| Services billed to Medicare | 124 |
| Different services or procedures | 10 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)48 services
- Insertion of needle into vein for collection of blood sample (36415)34 services
- Influenza vaccine, trivalent, 0.5 ml dosage (90658)11 services
- Administration of influenza virus vaccine (G0008)11 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 cholesterol75%
- High blood pressure68%
- Diabetes68%
Practice locations
Addresses where Maria G. Tan is enrolled with Medicare (CMS data updated October 2, 2026).
- 4501 Cartwright Rd, Suite 604Missouri City, TX 77459 (281) 499‑9609
- 454 PO BoxMissouri City, TX 77459
Specialties
- Family Practiceprimary
Other family doctors in Missouri City
Clinicians with the same Medicare primary specialty in Missouri City, TX — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1973 (53 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1689666158 |
| 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
- 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