John Michael Ioannou, M.D.
Internal Medicine · Nephrology (CMS) · Rockville Centre, NY
At a glance
242 Merrick Rd, Rockville Centre, NY 11570-5254
NPPES record updated Oct 30, 2009. 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
242 Merrick Rd Suite 304Rockville Centre, NY 11570-5254
Education & affiliations
- Medical / professional school
- Icahn School Of Medicine At Mount Sinai
- Graduation year
- 2001
- CMS specialties
- Internal Medicine · Nephrology
CMS reports telehealth services for this clinician. Confirm current services and availability with the practice.
Practice groups
Reported hospital affiliations
- Chsli St Joseph Hospital Bethpage, NY
- Mercy Medical Center Rockville Centre, NY
- Mount Sinai South Nassau Oceanside, 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
Includes reported transfers of value, such as meals, travel, or consulting. Payments do not establish improper conduct or quality of care. Research funding and ownership values are excluded from this total.
See payment purposes and reporting companies
Reported purposes
| Purpose | Amount |
|---|---|
| Food and beverage | $2,068.20 |
Reporting companies
| Company | Amount |
|---|---|
| BAYER HEALTHCARE PHARMACEUTICALS INC. | $309.27 |
| OTSUKA AMERICA PHARMACEUTICAL, INC. | $307.67 |
| ASTRAZENECA PHARMACEUTICALS LP | $157.30 |
| ARDELYX, INC. | $155.49 |
| NOVARTIS PHARMACEUTICALS CORPORATION | $147.42 |
| MALLINCKRODT HOSPITAL PRODUCTS INC. | $143.71 |
| BOEHRINGER INGELHEIM PHARMACEUTICALS, INC. | $105.32 |
| AMGEN INC. | $100.06 |
| Other reporting companies | $641.96 |
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 · Nephrology (CMS)
- Taxonomy code
- 207RN0300X
- Enumeration date
- Jun 6, 2006
- Record updated
- Oct 30, 2009
More registry details
- Provider type
- Individual · Type 1
- Reported credentials
- M.D.
Reported taxonomies and licenses
207RN0300X · Primary
License reported: 231998 NY
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
242 Merrick RdSuite 304
Rockville Centre, NY 11570-5254
- Phone
- (516) 764-7070
- Fax
- (516) 764-7073
Mailing address
242 MERRICK RDSUITE 304
ROCKVILLE CENTRE, NY 115705254
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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