Karen Hsu, MD
NPI 1659733459 · Obstetrics & Gynecology Physician · Orange, CA
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Karen Hsu, MD is a Obstetrics & Gynecology Physician provider in Orange, CA (NPI 1659733459).
Provider details
- NPI number
- 1659733459
- Entity type
- Individual
- Primary specialty
- Obstetrics & Gynecology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- A170534 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
10 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
15 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 15 | $179 |
Typical Medicare-allowed amounts for these services range $179–$179 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Estradiol | 23 | 13 |
| Clobetasol Propionate | 14 | — |
| Progesterone, Micronizedbrand: Progesterone | 13 | — |
| Estradiolbrand: Dotti | 13 | — |
| Misoprostol | 11 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$979 across 5 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (1)
- 350 E 17th St9bh26New York, NY 10003-3805Phone: (212) 420-4548Fax: (212) 420-2980
Registry dates
- Enumerated
- 2016-03-22
- Last updated
- 2020-12-01
- Certified
- 2020-12-01
Frequently asked questions
- What is Karen Hsu's NPI number?
- Karen Hsu's National Provider Identifier (NPI) is 1659733459, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Karen Hsu's specialty?
- Karen Hsu is listed in the NPPES registry with a primary specialty of Obstetrics & Gynecology Physician (Allopathic & Osteopathic Physicians).
- Where is Karen Hsu located?
- Karen Hsu's practice location on file with NPPES is 2501 E Chapman Ave Ste 201-202, Orange, CA 92869-3204.
- What is Karen Hsu's phone number?
- The practice phone number listed in the NPPES registry for Karen Hsu is (714) 282-1892.
- Does Karen Hsu accept Medicare?
- Karen Hsu is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Karen Hsu's NPI active?
- Yes — Karen Hsu's NPI (1659733459) is active in the NPPES registry as of the last update on 2020-12-01.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.