Christina O'brien, MD
Internal Medicine · Mount Kisco, NY
At a glance
400 E Main St, Mount Kisco, NY 10549-3477
NPPES record updated Nov 14, 2023. Public records can lag behind changes at a practice.
Before you call: a quick checklist
- Are you accepting new patients?
- Do you accept my specific insurance plan?
- Do you provide the service I need at this address?
- Do I need a referral, and what is the earliest appointment?
Insurance participation and appointment availability are not established by these public records.
Medicare & insurance
Insurance participation is not established by these public records. Ask the practice and your insurer about your specific plan and this location.
How to check your coverage
Use your plan’s provider directory or the member-services number on your insurance card. Confirm the clinician, practice address, service, and whether a referral is required. A missing opt-out record does not establish Medicare acceptance.
Check the official Medicare directory ↗Practice location
400 E Main StMount Kisco, NY 10549-3477
Additional reported practice locations
55 Lake Ave NWorcester, MA 01655
Phone: 5083341000 157 Union St
Marlborough, MA 017521228
Phone: 5084865678
Fax: 5084865677 119 Belmont St
Worcester, MA 016052903
Phone: 5083348515
Fax: 5083346490
Education & affiliations
- Medical / professional school
- Not reported in this file
- Graduation year
- 2017
- CMS specialties
- Internal Medicine
Practice groups
Reported hospital affiliations
- Lenox Hill Hospital New York, NY
- Northern Westchester Hospital Mount Kisco, NY
Graduation year does not establish years in practice. A reported affiliation does not establish employment, current admitting privileges, or insurance participation.
Source: CMS National Downloadable File · Published Oct 15, 2026.
Source: CMS Facility Affiliation Data · Published Oct 15, 2026.
Procedures in the public data
Reported activity can help you ask more informed questions about a practice’s services.
No displayed procedure-category record in this release. This does not mean the clinician performs no procedures.
CMS uses a one-year claims window with a reporting lag. Counts cover the Medicare activity included by CMS, not all patients. “1–10” is a published range. Volume is not a quality or outcomes score. Coverage and methodology
Source: CMS Utilization Data · Published Oct 15, 2026.
Find providers with a similar service mix
Compare 2024 published Medicare activity in the same reported specialty, here or in another city.
Industry-reported general payments
No matching general-payment summary in the imported release. This is not a verified zero and does not rule out other payment types or years.
Source: CMS 2025 payments grouped by covered recipient and nature of payments · Published Jun 30, 2026.
Professional details: NPI, taxonomy & registry record
Registry details
- Primary taxonomy
- Internal Medicine
- Taxonomy code
- 207R00000X
- Enumeration date
- Jun 5, 2017
- Record updated
- Nov 14, 2023
More registry details
- Provider type
- Individual · Type 1
- Reported credentials
- MD
Reported taxonomies and licenses
207R00000X
License reported: 317296 NY
207R00000X
License reported: MD2023-1322 NM
207R00000X · Primary
License reported: 281695 MA
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
400 E Main StMount Kisco, NY 10549-3477
- Phone
- (302) 383-9764
Mailing address
16 TALL PINES LNMOUNT KISCO, NY 105494108
Information may be outdated or incomplete. Confirm details directly with the practice. HCPList is an independent directory and is not affiliated with CMS.
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