Limitation on certain facility coverage.

The department shall determine, under a method devised by the department, the average population during the period from January 1, 1987, to June 30, 1988, of persons in each skilled nursing facility or an intermediate care facility who are mentally ill and are aged 21 to 64, except persons under 22 years of age who were receiving medical assistance services in the facility prior to reaching age 21 and continuously thereafter. Beginning July 1, 1988, the payment under sub. (6m) for services provided by a facility to persons who are mentally ill and are within the age limitations specified in this subsection may not exceed the payment for the average population of these persons in that facility, as determined by the department.