Patients First Act of 2003

Requires a suit to be brought within three years of the date of injury or one year after the claimant discovers or should have discovered the injury, whichever occurs first. Specifies exceptions when a suit may be brought later than three years after the date of injury.

Sets forth requirements and permissible recovery amounts for compensating patient injury, including: (1) the full amount of economic loss without limitation; (2) noneconomic damages as specified; and (3) a fair share rule.

Requires the court to supervise payment-of-damage arrangements, limiting contingency fees.

Sets forth rules for expert witnesses in cases concerning issues of negligence. States that such rules do not pertain to witnesses testifying to the degree or permanency of medical or physical impairment.

Permits the introduction of evidence of collateral source benefits, except that this section shall not apply to provisions of the Social Security Act pertaining to State plans for medical assistance and Medicare as secondary payer.

Limits the availability of punitive damages, requiring clear and convincing evidence of malicious intent to injure or a deliberate failure to avoid substantially certain, unnecessary injury. Prohibits their award for products that comply with Food and Drug Administration (FDA) standards, except if the manufacturer or distributor of a particular medical product or the supplier of a component or raw material of such a product causes harm by failing to comply with a specific requirement of the Federal Food, Drug and Cosmetic Act.

Authorizes periodic payment of future damages to claimants.

Excludes suits for vaccine-related death or injury from the requirements of this Act if otherwise covered under the National Vaccine Injury Compensation Program.

Preempts State law unless such law imposes greater protections for health care providers and organizations from liability, loss, or damages.

Expresses the sense of Congress that a health insurer should be liable for damages for harm caused when it makes a decision as to what care is medically necessary and appropriate.