Section 34M. Every motor vehicle liability policy and every motor vehicle liability bond, as defined in section thirty-four A, issued or executed in this commonwealth shall provide personal injury protection benefits as defined therein except to the extent such defined benefits to an insured or obligor or members of an insured's or obligor's household may be modified, reduced or eliminated by the purchase of the deductible authorized in this section. The benefits due and payable under any motor vehicle liability policy or bond as a result of the provisions therein providing personal injury protection benefits, and any benefits due any person entitled to make claim under the assigned claims plan established in accordance with section thirty-four N, are granted in lieu of damages otherwise recoverable by the injured person or persons in tort as a result of an accident occurring within this commonwealth.

Every owner, registrant, operator or occupant of a motor vehicle to which personal injury protection benefits apply who would otherwise be liable in tort, and any person or organization legally responsible for his acts or omissions, is hereby made exempt from tort liability for damages because of bodily injury, sickness, disease or death arising out of the ownership, operation, maintenance or use of such motor vehicle to the extent that the injured party is, or would be had he or someone for him not purchased a deductible authorized by this section, entitled to recover under those provisions of a motor vehicle liability policy or bond that provide personal injury protection benefits or from the insurer assigned. No such exemption from tort liability shall apply in the case of an accident occurring outside the commonwealth. However, if any person claiming or entitled to benefits under the personal injury protection provisions of a policy or bond insuring a vehicle registered in this commonwealth brings, in such a case, an action in tort against the owner or person responsible for the operation of such a vehicle, amounts otherwise due such a person under the provisions of section thirty-four A shall not become due and payable until a settlement is reached or a final judgment is rendered in such a case and the amounts then due shall be reduced to that extent that damages for expenses and loss otherwise recoverable as a personal injury protection benefit are included in any such settlement or judgment.

Claim for benefits due under the provisions of personal injury protection or from the insurer assigned shall be presented to the company providing such benefits as soon as practicable after the accident occurs from which such claim arises, and in every case, within at least two years from the date of accident, and shall include a written description of the nature and extent of injuries sustained, treatment received and contemplated and such other information as may assist in determining the amount due and payable. If benefits for loss of wage or salary, or in the case of the self-employed their equivalent, are claimed the party presenting such a claim shall authorize the insurer to obtain details of all wage or salary payments, or their equivalent, paid to him by any employer in the year immediately preceding the date of accident, or earned by him, and authorize the insurer to make any reasonable necessary investigation as to whether or not such loss may be reduced in whole or in part as a result of any program calling for the continuance of such wage, salary or earnings during absence from work. The injured person shall submit to physical examinations by physicians selected by the insurer as often as may be reasonably required and shall do all things necessary to enable the insurer to obtain medical reports and other needed information to assist in determining the amounts due. Noncooperation of an injured party shall be a defense to the insurer in any suit for benefits authorized by this section and failure of an insurer to pay benefits in the event of such noncooperation shall not in any way affect the exemption from tort liability granted herein.

Personal injury protection benefits and benefits due from an insurer assigned shall be due and payable as loss accrues, upon receipt of reasonable proof of the fact and amount of expenses and loss incurred provided that upon notification of disability from a licensed physician, the insurer shall commence medical payments within ten days or give written notice of its intent not to make such payments, specifying reasons for said nonpayment, but an insurer may agree to a lump sum discharging all future liability for such benefits on its own behalf and on behalf of the insured. With respect to such benefits, and to medical coverage contained in section one hundred and thirteen C of chapter one hundred and seventy-five, no insurer shall refuse to pay a bill for medical services submitted by a practitioner registered or licensed under the provisions of chapter one hundred and twelve, if such refusal is based solely on a medical review of the bill or of the medical services underlying the bill, which review was requested or conducted by the insurer, unless the insurer has submitted, for medical review, such bill or claim to at least one practitioner registered or licensed under the same section of chapter one hundred and twelve as the practitioner who submitted the bill for medical services. In any case where benefits due and payable remain unpaid for more than thirty days, any unpaid party shall be deemed a party to a contract with the insurer responsible for payment and shall therefore have a right to commence an action in contract for payment of amounts therein determined to be due in accordance with the provisions of this chapter. In any such action commenced in the district court in the judicial district in which the unpaid party resides, the court shall, upon the filing of an answer by the insurer and upon the motion of the unpaid party, advance the action for a speedy trial. If the unpaid party recovers a judgment for any amount due and payable by the insurer, the court shall assess against the insurer in addition thereto costs and reasonable attorney's fees.

Any insurer paying benefits in accordance with the provisions of this section shall be subrogated to that exact extent to the rights of any party it pays and may bring an action in tort against any person liable for such damages in tort who is not exempt from said liability as a result of the provisions of this section; provided, however, that no insurer shall reduce or limit the amount of liability insurance otherwise available to an injured person as a result of such subrogation. Said insurer is also hereby given the right to make claim for all expenses it incurs on account of such payments, including the net amount of benefits paid, costs of processing claims for any such benefits, and the expenses of enforcing this right, against any other insurer providing a motor vehicle liability policy or bond on a motor vehicle registered in this commonwealth, whose owner or operator would, except for the exemption from tort liability provided in this section, be liable for such damages in tort. Determination as to whether any insurer is legally entitled to recover any such expense from another insurer shall be made by agreement between the involved insurers, or, if they fail to agree, by arbitration in accordance with the provisions of the General Laws.

Each insurer providing personal injury protection shall issue to any person purchasing a motor vehicle liability policy or bond, at his option, a policy endorsement, approved as to content by the commissioner of insurance and subject to such other regulations regarding said endorsement as the commissioner may from time to time make after appropriate hearing, which shall provide that there shall be deducted from amounts that would otherwise be or become due to the policyholder alone or to the policyholder and members of his household, as the policyholder elects, an amount of either one hundred dollars, two hundred and fifty dollars, five hundred dollars, one thousand dollars, two thousand dollars, four thousand dollars or eight thousand dollars, again as the policyholder elects, said amount to be deducted from the amounts otherwise due each person subject to the deduction. Any person electing such an endorsement or subject to such an endorsement as a result of the policyholder's election shall have no right to claim or to recover any amount so deducted from any owner, registrant, operator or occupant of a motor vehicle or any person or organization legally responsible for any such owner's, registrant's, operator's or occupant's acts or omissions who is made exempt from tort liability by this section.

Amounts deducted from payment in accordance with the provisions of the preceding paragraph shall not have any effect upon the determination of whether or not the reasonable and necessary expenses incurred as a result of any injury exceed or do not exceed five hundred dollars, which determination may affect an injured's person's rights under section six D of chapter two hundred and thirty-one.