Prescription Guarantee Act of 1998

Prescription Guarantee Act of 1998 - Amends the Public Health Service Act and the Employee Retirement Income Security Act of 1974 to require a group health plan, or a health insurance issuer offering coverage in connection with a group plan, if it covers prescription drugs but limits benefits to (or provides more favorable benefits for) drugs in a formulary, to: (1) make available to the public on request a description of the formulary restrictions; and (2) provide for restriction exceptions when the plan or beneficiary's physician, subject to reasonable plan or issuer review, determines that a non-formulary alternative is medically beneficial based on a therapeutic difference to the patient involved. Allows copayment doubling for nonformulary drugs. Prohibits a plan that provides prescription drug coverage from denying coverage of a drug if the use is included in the labeling authorized under specified provisions of the Federal Food, Drug, and Cosmetic Act. Prohibits a plan or issuer from discriminating against a health professional based on the extent, type, or pattern of prescription drugs. Prohibits a plan or issuer from excluding a pharmacist from its network if the pharmacist is willing to enter into a contract to provide drugs at the rate prescribed by the plan or issuer. Amends the Public Health Service Act to apply the above requirements to issuers offering coverage in the individual market. Amends the Health Insurance Portability and Accountability Act of 1996 to modify requirements regarding coordination by the Secretaries of the Treasury, Health and Human Services, and Labor regarding regulations, rulings, interpretations, and policies relating to the Act.