ANN ZERA TAN (M.D.) – Anatomic Pathology & Clinical Pathology Physician, NPI 1093976938
Anatomic Pathology & Clinical Pathology Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
1,584 PATHOLOGY in CA
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Provider Addresses for ANN ZERA TAN (M.D.)
Shakespeare Drive, San Marino, Los Angeles County, California, 91775, United States
SAN MARINO, CA 911082230
Phone: (323) 226-7149
Type: Mailing
1200, North State Street, Boyle Heights, Los Angeles, Los Angeles County, California, 90033, United States
LOS ANGELES COUNTY MEDICAL CENTER, GH ROOM 2900
LOS ANGELES, CA 900331029
Phone: (323) 226-7149
Type: Location
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
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Open Payments (CMS)
CMS reports 1 Open Payments records for all available years, with a total value of $21.
Total Amount is formed as General ($21) + Research ($0) + Ownership ($0) = $21.
Last reported payment date: 2024-04-17 • Largest payer in this snapshot: Merck Sharp & Dohme LLC ($21).
Total Amount
$21
General + Research + Ownership
Payments
1
Total payment records
General Amount
$21
General payments
Research Amount
$0
Research funding
Ownership Amount
$0
Ownership interests
Ownership Count
0
Ownership records
Last Payment Date
2024-04-17
Latest reported date
Top Companies
Largest payers in this snapshot
| Company | Amount |
|---|---|
| Merck Sharp & Dohme LLC | $21 |
Medicare Enrollment & Revalidation
Source: CMS public data · Not endorsed by CMS ·
Educational use only—not medical, billing, or legal advice.
PECOS enrollment status
Participating (accepts Medicare assignment)
Enrollment effective: 2009-07-08
PECOS data refreshed: 2026-05-27
Medicare revalidation (CMS due date list)
Due date not assigned yet
CMS is tracking this Medicare enrollment for revalidation, but has not published a due date.
Enrollment records
1
Earliest due date
Not assigned (TBD)
CMS data updated
2026-06-01
Revalidation progress
- Medicare enrolled
- On CMS revalidation list
- Due date assigned
- Revalidate in PECOS
CMS enrollment records
| Enrollment ID | Type | Specialty | State | Due date |
|---|---|---|---|---|
| I20090708000544 | I | Pathology | CA | TBD |
What to do next
- No action required while the due date shows TBD.
- Check the CMS Revalidation Lookup Tool periodically — CMS updates the list about every 60 days.
- Do not submit a revalidation application in PECOS until CMS publishes a concrete due date.
Prepare CMS-855 application → · Look up this NPI in PECOS → · Verify on CMS PECOS
Medicare Utilization (FFS)
Source: CMS public data · Not endorsed by CMS · Beneficiary counts under 11 are suppressed in source data ·
Educational use only—not medical, billing, or legal advice.
Top Medicare procedures (2023) · refreshed 2026-05-27
| HCPCS | Description | Services | Beneficiaries | Medicare allowed |
|---|---|---|---|---|
| 88305 | Pathology examination of tissue using a microscope, intermediate complexity | 642 | 279 | $0 |
| 88331 | Pathology examination of specimen during surgery, first tissue block | 168 | 49 | $0 |
| 88311 | Preparation of tissue for examination by removing any calcium present | 125 | 98 | $0 |
| 88342 | Special stained specimen slides to examine tissue, initial procedure | 97 | 94 | $0 |
| 88341 | Special stained specimen slides to examine tissue, each additional procedure | 75 | 19 | $0 |
Insurance plans in this area (ZIP 91108)
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Group practice members
| Name | Specialty | State |
|---|---|---|
| P A T H O L O G Y | CA | |
| P A T H O L O G Y | CA | |
| P A T H O L O G Y | CA | |
| P A T H O L O G Y | OH | |
| P A T H O L O G Y | ME | |
| P A T H O L O G Y | CA |
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