La. Code Civ. Proc. art. 1475

A.(1) Unless a controverting affidavit is filed as provided for in this Article, an affidavit establishing medical services and costs shall be sufficient evidence to support a finding of fact by a judge or jury that the bill is authentic.

(2) The affidavit shall be made either by the person who provided the medical service or by the official custodian in charge of the medical records. The affidavit shall be accompanied by an itemized statement which shall set forth with specificity the medical service provided and the corresponding charge.

(3) The party submitting the affidavit in evidence shall file the affidavit with the clerk of court and serve a copy of the affidavit on other parties and all persons affected thereby at least thirty days before the trial.

B.(1) Any party intending to contravene the affidavit shall file a counter affidavit with the clerk of court and serve a copy of the counter affidavit on the other party or party's attorney of record not later than fifteen days after receipt of a copy of the affidavit and at least ten days before the trial or at any time before the trial with leave of court.

(2) The counter affidavit shall establish a reasonable basis on which the party intends to controvert the claim set forth in the initial affidavit and shall be made by a person who is qualified either by knowledge, skill, experience, training, or education, to testify in contravention of all or part of any matters contained in the initial affidavit.

C. If a counter affidavit is filed, and after opportunity for hearing, a party who fails to establish to the court's satisfaction that the medical statements are not authentic shall be required to pay to the initial affiant all costs and expenses incurred as a result of the hearing. The court may waive assessment of costs and expenses if it finds that the counter affidavit was substantially justified or that other circumstances make an award of expenses unjust.