In principle, rules may be made retroactive if it is reasonable to do so. The Minnesota Legislature has provided, however, that no law or rule is to be construed as retroactive unless clearly and manifestly so intended by the legislature. The definition of a rule in the APA, furthermore, provides that the rule is to have “future effect.” But similar language in the federal APA has been construed as not precluding retroactive regulation. In addition, the Minnesota APA also provides that a properly adopted rule, regardless of whether it is substantive, procedural, or interpretative, “has the force and effect of law retroactive to the date on which the rule became effective.”
 Mason v. Farmers Ins. Cos., 281 N.W.2d 344, 348 (Minn. 1979)
 Minn. Stat. § 645.21 (2014); Minn. League of Credit Unions v. Minn. Dep’t of Commerce, 486 N.W.2d 399, 405 (Minn. 1992) (stating law can ordinarily be applied only prospectively unless the legislature expressly declares or clearly and manifestly intends it to be applied retroactively).
 Minn. Stat. § 14.02, subd. 4 (2014).
 Summit Nursing Home v. United States, 572 F.2d 737, 742 (Ct. Cl. 1978).
 Minn. Stat. § 14.38, subd. 2 (2014).