Quick answers
- Does Margaret O. Chapman accept Medicare assignment?
- Medicare's clinician data says Margaret O. Chapman may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- How many Medicare patients does Margaret O. Chapman see?
- In 2024, CMS data shows 16 Original Medicare patients and 33 services for Margaret O. Chapman. This counts Original Medicare only and measures volume, not quality.
- What is Margaret O. Chapman's NPI number?
- 1306084470. 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 Margaret O. Chapman, 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 | 16 |
|---|---|
| Services billed to Medicare | 33 |
| Different services or procedures | 10 |
| Participating Medicare provider | Yes |
| Average age of these patients | 70 |
Practice locations
Addresses where Margaret O. Chapman is enrolled with Medicare (CMS data updated October 2, 2026).
- 1 Embarcadero Ctr, Suite 1900San Francisco, CA 94111
- 129 W 29th St, Fl 10New York, NY 10001
Specialties
- Pediatric Medicineprimary
Other pediatricians in San Francisco
Clinicians with the same Medicare primary specialty in San Francisco, CA — not a recommendation.
Clinician information
| Graduation year | 1993 (33 years since medical school) |
|---|---|
| Gender (as listed) | Female |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1306084470 |
| 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