Preventing Addiction for Susceptible Seniors Act of 2018 or the PASS Act of 2018 (Sec. 2) This bill alters several requirements under the Medicare prescription drug benefit. Specifically, the bill requires electronic prescription programs to enable the secure transmittal of prior authorization requests for covered drugs. (Sec. 3) The bill also requires the Centers for Medicare & Medicaid Services (CMS) to establish a secure online portal to allow: (1) data sharing among the CMS, Medicare prescription drug benefit plans, and Medicare Advantage (MA) plans; and (2) referrals by such plans of substantiated fraud, waste, or abuse in order to initiate or assist investigations by contracted entities under the Medicare Integrity Program. (Sec. 4) The bill also establishes individuals who are identified as at-risk beneficiaries for prescription drug abuse as qualifying participants in medication therapy management programs under the Medicare prescription drug benefit. (Sec. 5) The CMS must also: (1) identify outlier prescribers of opioids under Medicare prescription drug benefit plans and MA plans, based on specialty and geographic area; and (2) annually notify such prescribers of their status and provide them with resources on proper prescribing methods.