95-175 provided the OVS with a new right to a statutory lien on the applicant's recovery against the wrongdoer, in addition to its preexisting subrogation and reimbursement rights, and gave it the authority to abrogate these lien rights and subrogation rights in the circumstances specified. Your office has asked several questions regarding the applicability of Public Act 95-175 to claims filed and awards made at various times relative to the effective date of the Act, October 1, 1995. The answers to most of these questions and their subparts turn upon whether Public Act 95-175 should be applied retroactively or prospectively. As a general rule, the law disfavors the retroactive application of a statute effecting substantive, as opposed to procedural, changes. Statutes are applied retroactively in a very narrow category of cases.
Retroactive application is the rule for amending statutes that are procedural in their impact. . . .
An act that has been passed to clarify an existing statute, that is, one that was passed shortly after controversies arose as to the judicial interpretation of the original act, is also to be applied retroactively. All other statutes are applied prospectively unless the legislature expressly specifies the contrary. These aids to legislative interpretation apply with equal force to amendatory acts which effectuate changes in existing statutes. Thus, a statute affecting vested rights or imposing new obligations is construed to apply prospectively unless the legislature clearly and unequivocally expresses its intent that the legislation shall apply retrospectively. A lien is a proprietary interest and a property right, even though it does not confer title to or possession in the property involved.