The commissioner shall apply for any federal waivers necessary to secure, to the extent allowed by law, federal financial participation for the provision of services to persons who need substance use disorder services. The commissioner may seek amendments to the waivers or apply for additional waivers to contain costs. The commissioner shall ensure that payment for the cost of providing substance use disorder services under the federal waiver plan does not exceed the cost of substance use disorder services that would have been provided without the waivered services.