Mount Sinai South Nassau in Oceanside, NY
Also known as MSSN
In a medical emergency, call 911. This page is for information only.
About Mount Sinai South Nassau
Mount Sinai South Nassau is an acute care hospital in Oceanside, Nassau County, New York. It reports its ownership to Medicare as nonprofit (private). It provides emergency services. It is listed as a Level II trauma center. Its CMS Overall Hospital Quality Star Rating is 3 out of 5. It has 455 licensed beds, according to state license data via HIFLD. It meets the CMS Birthing-Friendly designation criteria for maternity care. The nearest other listed hospital is Mercy Medical Center, about 2.4 mi away.
Quality ratings
How this hospital compares with the national rate on each measure group:
Source: Centers for Medicare & Medicaid Services, Hospital General Information. How star ratings work.
Emergency room times
Lower times are better. Reporting period ending September 2025. Source: CMS Timely and Effective Care. What these numbers mean.
Infections and sepsis care
- MRSA bloodstream infectionsNo different · SIR 0.58
- Catheter-associated urinary tract infections (CAUTI)No different · SIR 0.45
- Clostridioides difficile (C. diff) infectionsBetter than national · SIR 0.16
- Central line bloodstream infections (CLABSI)Better than national · SIR 0.00
- Surgical site infections after abdominal hysterectomyNo different · SIR 2.96
- Surgical site infections after colon surgeryBetter than national · SIR 0.18
78% of patients with severe sepsis or septic shock received all the recommended early care steps (SEP-1). Higher is better.
SIR is the standardized infection ratio: below 1 means fewer infections than predicted for a hospital like this one. Period ending September 2025. Source: CMS Healthcare-Associated Infections and Timely and Effective Care.
What patients say
- Patient survey star rating
- Would definitely recommend62%
- Rated the hospital 9 or 1061%
- Completed surveys861
Survey period ending September 2025. Source: CMS HCAHPS Patient Survey.
Map
40.65179, -73.63041
Nearby hospitals
- Mercy Medical Center1000 North Village Avenue, Rockville Centre, NY · Emergency roomAcute care hospital2.4 mi
- NYU Langone Hospital Long Island259 1st Street, Mineola, NY · Level I traumaHospital6.2 mi
- Nassau University Medical Center2201 Hempstead Turnpike, East Meadow, NY · Level I traumaAcute care hospital6.4 mi
- St John's Episcopal Hospital at South Shore327 Beach 19th Street, Far Rockaway, NY · Emergency roomAcute care hospital7.4 mi
- Creedmoor Psychiatric Center80-45 Winchester Blvd Bldg B, Queens Village, NYPsychiatric hospital7.9 mi
- Zucker Hillside Hospital75-59 263rd Street, Glen Oaks, NYPsychiatric hospital8.1 mi
- Long Island Jewish Medical Center270 - 05 76th Avenue, New Hyde Park, NY · Emergency roomAcute care hospital8.1 mi
- Katz Women's Hospital270-05 76th Avenue, New Hyde Park, NYHospital8.2 mi
- New York City Childrens Psych Center7403 Commonwealth Blvd, Bellerose, NYPsychiatric hospital8.3 mi
- Jamaica Hospital Medical Center111-20 Merrick Boulevard, Queens, NYHospital8.4 mi
Frequently asked questions
Where is Mount Sinai South Nassau located?
Mount Sinai South Nassau is at One Healthy Way, Oceanside, NY 11572 in Nassau County.
Does Mount Sinai South Nassau have an emergency room?
Yes. Mount Sinai South Nassau reports emergency services to Medicare, and patients spent a median of 219 minutes in its emergency department before leaving. In a life-threatening emergency, call 911.
What is the CMS star rating of Mount Sinai South Nassau?
Mount Sinai South Nassau has a CMS Overall Hospital Quality Star Rating of 3 out of 5. The rating combines measures of mortality, safety of care, readmission, patient experience and timely and effective care, compared with hospitals nationwide.
Is Mount Sinai South Nassau a trauma center?
Yes. It is listed as a Level II trauma center in the HIFLD hospitals data, which is compiled from state trauma registries (source date April 2024). Trauma designations are renewed periodically, so confirm with the New York EMS or trauma program. In an emergency, call 911: paramedics take seriously injured patients to the right trauma center.
What is the phone number of Mount Sinai South Nassau?
The main phone number on record with Medicare is (516) 632-3000.
Would patients recommend Mount Sinai South Nassau?
In the most recent HCAHPS patient survey (861 completed surveys), 62% of patients said they would definitely recommend the hospital, and 61% rated it 9 or 10 out of 10.
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