(a) In any civil action in which a verdict is rendered or a decision made for pecuniary damages, there shall be added by the clerk of the court to the amount of damages interest at the rate of twelve percent (12%) per annum thereon from the date the cause of action accrued, which shall be included in the judgment entered therein. Post-judgment interest shall be calculated at the rate of twelve percent (12%) per annum and accrue on both the principal amount of the judgment and the prejudgment interest entered therein. This section shall not apply until entry of judgment or to any contractual obligation where interest is already provided.
(b) Subsection (a) shall not apply in any action filed on or after January 1, 1987, for personal injury or wrongful death filed against a licensed physician, hospital, clinic, health maintenance organization, professional service corporation providing health care services, dentist, or dental hygienist based on professional negligence. In all such medical malpractice actions in which a verdict is rendered or a decision made for pecuniary damages, there shall be added by the clerk of the court to the amount of damages interest at the rate of twelve percent (12%) per annum thereon from the date of written notice of the claim by the claimant or his or her representative to the malpractice liability insurer, or to the medical or dental health care provider or the filing of the civil action, whichever first occurs.