Minn. Stat. § 62J.25: MANDATORY MEDICARE ASSIGNMENT.

(a) Effective January 1, 1993, a health care provider shall not charge to or collect from a Medicare beneficiary who is a Minnesota resident any amount in excess of 115 percent of the Medicare-approved amount for any Medicare-covered service provided.

(b) Effective January 1, 1994, a health care provider shall not charge to or collect from a Medicare beneficiary who is a Minnesota resident any amount in excess of 110 percent of the Medicare-approved amount for any Medicare-covered service provided.

(c) Effective January 1, 1995, a health care provider shall not charge to or collect from a Medicare beneficiary who is a Minnesota resident any amount in excess of 105 percent of the Medicare-approved amount for any Medicare-covered service provided.

(d) Effective January 1, 1996, a health care provider shall not charge to or collect from a Medicare beneficiary who is a Minnesota resident any amount in excess of the Medicare-approved amount for any Medicare-covered service provided.

(e) This section does not apply to ambulance services as defined in section 144E.001, subdivision 3, or medical supplies and equipment. A vendor of medical supplies and equipment that does not accept assignment under the federal Medicare program with respect to a purchase or lease of Medicare-covered supplies or equipment shall notify any purchaser who is a Medicare beneficiary and Minnesota resident, prior to the purchase, or at any time upon the request of the purchaser, that the vendor charges an amount in excess of the Medicare-approved amount.