incorporated into the insurance contract, was triggered. While Andary and Krueger could not seek
reimbursement for specific medical expenses until the expenses were actually incurred under MCL
500.3110(4), their rights under the insurance policies for reimbursement of all reasonable and
necessary medical expenses at a particular (uncapped) level vested at the time of the automobile
accidents causing their injuries—the events that triggered the coverage provided by the insurance
policies.
4. In determining whether a law has retroactive effect, four principles are considered. First,
a court considers whether there is specific language providing for retroactive application. Second,
in some situations, a statute is not regarded as operating retroactively merely because it relates to
an antecedent event. Third, retroactive laws impair vested rights acquired under existing laws or
create new obligations or duties with respect to transactions or considerations already past.
Finally, a remedial or procedural act not affecting vested rights may be given retroactive effect
where the injury or claim is antecedent to the enactment of the statute. In this case, under the first
factor, the amendments that 2019 PA 21 made to MCL 500.3157(7) and (10) appeared prospective
on their face, but these provisions did not explicitly address to whom they apply. There was
nothing in the clear language of MCL 500.3157, as amended by 2019 PA 21, that suggested an
intent to modify the contractual rights of an injured individual who has uncapped PIP benefits and
family-provided attendant care that vested prior to the enactment of the amendments. Under MCL
500.2111f(8), any savings from the class of individuals injured before July 1, 2021, who have no
vested right to benefits at the pre-amendment level must be passed on in filings after July 1, 2020.
However, MCL 500.2111f(8) does not reflect a clear expression of legislative intent that MCL
500.3157(7) and (10) apply retroactively to insureds who were injured while covered by an
insurance policy providing them a contractual right to provider reimbursement at the pre-
amendment levels. Under the second factor, MCL 500.3157(7) and (10) do not directly relate to
antecedent events because, on their face, they apply to all services and care rendered after the listed
effective dates. Accordingly, while application of the amended statutes to individuals like Andary
and Krueger indirectly relates to antecedent car crashes and injuries, which triggered their rights
to PIP benefits, this was not enough on its own to render the statute retroactive as to required
benefits. But this consideration was not dispositive because the statutes are properly considered
retroactive as applied to Andary and Krueger given that application would impair their vested
contractual rights to PIP benefits at the pre-amendment level. Under the third factor, the
application of MCL 500.3157(7) and (10) to Andary and Krueger would impair their vested
contractual rights to PIP reimbursement for medical treatment at a particular level. When the
insurance policies were issued and when Andary’s and Krueger’s injuries occurred, the policies
provided no less than what the no-fault act required, and this guarantee was both contractual and
statutory in nature. As a result, Andary and Krueger were entitled to enforce the rights that vested
under the original contractual bargain absent clear legislative intent to retroactively modify that
arrangement. Under the fourth factor, given that Andary’s and Krueger’s rights vested at the time
of their injuries, this factor did not apply, even if the amendments were intended to remedy
perceived problems with the previous system of no-fault automobile insurance. Accordingly, the
insurance policies and the disputed portion of the no-fault statutes that existed when Andary and
Krueger were injured controlled their entitlement to PIP benefits, not the amended provisions
enacted by 2019 PA 21 and 2019 PA 22.
5. Plaintiffs lacked standing to maintain due-process and equal-protection challenges as to
the prospective application of MCL 500.3157(7) or (10) on behalf of nonparties. Because due-