Margaret Xu, MD
Margaret Xu, MD is a Geriatric Medicine (Internal Medicine) Physician in New Haven, CT, registered under NPI 1003435280.
Getting there
Here is what surrounds this office in New Haven, based on OpenStreetMap data collected Sep 2, 2026. Parking is available about 0.34 mi away at Howe Street Garage. There is EV charging 0.35 mi from the office — useful if you are driving in from out of town. The nearest transit stop is 715 ft away, served by 129 York. A pharmacy sits 0.37 mi from the entrance (Rite Aid), which helps if you leave with a prescription. If you arrive early, there is a coffee shop 0.25 mi away.
Getting here and what is nearby
Restaurant Dunkin' 4 ft ~1 min
51 York Street, New Haven 06511
Mo-Fr 04:30-18:00; Sa-Su 04:30-17:00
Convenience Sam's Food 85 ft ~1 min
Restaurant Subway 92 ft ~1 min
66 York Street, New Haven 06511
Mo-Sa 10:00-22:00; Su 11:00-21:00
Pharmacy Walgreens 403 ft ~2 min
88 York Street, 06511
Transit 333 Cedar 680 ft ~3 min
Transit 129 York 714 ft ~3 min
Transit 129 York 715 ft ~3 min
Restaurant Super Sandwich 892 ft ~4 min
Coffee Prince Tea House 0.20 mi ~5 min
Coffee Midpoint 0.22 mi ~5 min
248 Crown Street, New Haven 06511
Mo,We,Th 08:00-21:00; Fr,Sa 08:00-23:00; Su 08:00-20:00
Parking Temple Medical Garage 0.22 mi ~5 min
Hotel New Haven Hotel 0.24 mi ~5 min
229 George Street, New Haven 06510
Coffee La Cocinita 0.25 mi ~5 min
Parking Howard Avenue Garage 0.25 mi ~5 min
790 Howard Avenue, New Haven 06519
Convenience COOK 2GO 0.27 mi ~6 min
1064 Chapel Street, New Haven 06510
Mo-Fr 07:00-00:00; Sa 07:00-01:00; Su 07:00-19:00
Convenience College Convenience 0.28 mi ~6 min
258 College Street, New Haven 06510
Hotel Graduate by Hilton New Haven 0.28 mi ~6 min
Hotel Cambria Hotel New Haven University Area 0.31 mi ~7 min
Pharmacy Chapel Street Pharmacy 0.32 mi ~7 min
Mo-Fr 09:00-18:00; Sa 09:00-13:00
Parking Howe Street Garage 0.34 mi ~7 min
67-81 Howe Street, New Haven 06511
EV charging 0.35 mi ~7 min
Pharmacy Rite Aid 0.37 mi ~8 min
Mo-Fr 08:00-20:00; Sa,Su 09:00-21:00
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 66101 | CT | Geriatric Medicine (Internal Medicine)… primary |
This provider holds licence 66101 issued in CT. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Geriatric Medicine
- PAC ID
- 7012330582
- Enrollment ID
- I20240731003587
Medicare enrolment is recorded as approved under the provider type Practitioner - Geriatric Medicine. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Geriatric Medicine covers
An internist who has special knowledge of the aging process and special skills in the diagnostic, therapeutic, preventive and rehabilitative aspects of illness in the elderly. This specialist cares for geriatric patients in the patient's home, the office, long-term care settings such as nursing homes and the hospital. NUCC Health Care Provider Taxonomy, code 207RG0300X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1003435280 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 8, 2020 |
| Last updated | Feb 2, 2024 |
| Status | Active |
| Sole proprietor | No |
| Gender | Female |
| Credential | MD |
| Practice address |
20 YORK ST New Haven, CT 06510 (203) 688-4242 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 0 | 0 | 3 | 4 | 3 | 5 | 2 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 8 | 3 | 1 | 2 | 7 |
Sum = 50 · next multiple of 10 = 50 · check digit = 0 · actual last digit = 0
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.