Slacks implies pants of certain materials which are not part of a suit (jeans are not slacks, and you would not refer to the pair of trousers that came with a suit as slacks.) It is also more common to use slacks to refer to pants worn by women, while men would wear trousers.
Health care safety net providers are those that have a legal mandate or mission to offer medical care to all patients, regardless of their ability to pay, and have a substantial number of patients who are uninsured or on Medicaid.
Healthcare Reimbursement to Doctors and Hospitals. Healthcare providers are paid by insurance or government payers through a system of reimbursement. They provide medical services to a patient and then file for reimbursement for those services with the insurance company or government agency.