Mass. Gen. Laws ch. 93 § 74
Every person who sells a hearing aid shall accompany such sale with a receipt that shall include: the name, address and signature of the purchaser; the date of consummation of the sale; the name and address of the regular place of business and the signature of the seller; the make, model, serial number and purchase price of the hearing aid; a statement whether the hearing aid is new, used or reconditioned; the terms of the sale, including an itemization of the total purchase price, including but not limited to the cost of the hearing aid, the earmold, any batteries or other accessories, and any service costs; a clear and precise statement of any guarantee or trial period; and shall also include the following printed statement in ten point type or larger: "This hearing aid will not restore normal hearing nor will it prevent further hearing loss. The sale of a hearing aid is restricted to those individuals who have obtained a medical evaluation from a licensed physician or otolaryngologist. A fully informed adult whose religious or personal beliefs preclude consultation with a physician may waive the requirement of a medical evaluation. The exercise of such a waiver is not in your best health interest and its use is strongly discouraged. It is also required that a person under the age of eighteen years obtain an evaluation by an audiologist in addition to the medical evaluation before a hearing aid can be sold to such person."
A copy of the medical clearance statement and audiological evaluation, where required, for the hearing aid shall be attached to the receipt.
Upon the date that the purchaser receives the hearing aid, the seller shall provide a delivery receipt signed by the seller and the purchaser which states the date of delivery to the purchaser of the hearing aid.
The seller shall keep records for every customer to whom he renders services or sells a hearing aid including a copy of such receipt, a copy of the medical clearance and the audiological evaluation, a copy of the delivery receipt, a record of services provided, and any correspondence to or from the customer. Such records shall be preserved for at least four years after the date of the last transaction.
Mass. Gen. Laws ch. 93, § 74