The answer
Do I need Medicare if I'm still working at 65?
Not necessarily; whether you need Medicare at 65 while working depends on your employer's size and your coverage.
If you have active health coverage through a job with 20 or more employees, where you or your spouse still work, you can usually delay Part B (medical) without penalty and enroll later through a Special Enrollment Period. If your employer has fewer than 20 employees, Medicare often becomes the primary payer, so signing up at 65 usually makes sense to avoid coverage gaps. Many people still enroll in premium-free Part A (hospital) at 65 even while working, though that choice interacts with health savings accounts.