I zeroed an employee's payroll allocation but they still receive benefits.

This may be because you have not changed the start date for the employee.

If you have an employee's start date set as January 1st, and have budgeted for them to receive benefits (Health Insurance etc) using the HR Formulas, then those benefits will begin on January 1st.

If things change, and it appears that the new employee will now not start until March 1st, you should go to Employees > Manage Employees and change their start date.

If you instead just zero the payroll allocation for January and February in the Manage Payroll edit screen for that employee, the benefits will still be applied from January 1st, as they begin on the official start date.