Mich. Comp. Laws § 500.731

Sec. 731. The following minimum morbidity standards for disability benefits for group health insurance certificates shall be used: (a) For contract reserves for policies and certificates issued on or after the effective date of this chapter, the 1987 commissioners group disability income table (87 C.G.D.T.). (b) For claim reserves for claims incurred prior to, on, or after the effective date of this chapter, the 1987 commissioners group disability income table (87 C.G.D.T.).