| Business | Phone |
| Quest Diagnostics Inc 887 Old Country Rd, Riverhead 11901 | (631) 369-6875 |
| Riverhead Diagnostic & Rehab 1149 Old Country Rd # A, Riverhead 11901 | (631) 208-3584 |
| Laboratory Corp Of America 1149 Old Country Rd # E2, Riverhead 11901 | (631) 369-0390 |