Alaska Comm. R. Evid. 409
The considerations underlying this rule parallel those underlying Rules 407 and 408, which deal respectively with subsequent remedial measures and offers of compromise. As stated in Annot., 20 A.L.R.2d 291, 293 (1951):
[G]enerally, evidence of payment of medical, hospital, or similar expenses of an injured party by the opposing party, is not admissible, the reason often given being that such payment or offer is usually made from humane impulses and not from an admission of liability, and that to hold otherwise would tend to discourage assistance to the injured person.
Contrary to Rule 408, dealing with offers of compromise, the present rule does not extend to conduct or statements not a part of the act of furnishing or offering or promising to pay. This difference in treatment arises from fundamental differences in nature. Communication is essential if compromises are to be effected, and consequently broad protection of statements is needed. This is not so in cases of payments or offers or promises to pay medical expenses, where factual statements may be expected to be incidental in nature and where protecting such statements would not encourage the approved behavior. A party can offer to pay medical expenses without making statements as to liability.
This rule, unlike Rule 408, does not require that liability or amount be in dispute. Prompt payment of medical and other expenses is encouraged and the humanitarian nature of the payment or offer is highlighted.
If liability or amount is in dispute, an offer to pay medical expenses may be part of a compromise negotiation. Once the offer becomes part of the negotiating process, any statements or conduct made in compromise negotiations will be protected under Rule 408.
Evidence of an offer to pay or of a completed payment of medical expenses may be admissible for purposes other than proving liability or amount. In this respect the rule is like Rule 408. When the issue upon which the evidence is offered is collateral to the merits of the case, admission may be proper. For example, if A is involved in an accident with B and C, and A pays B's medical expenses, C may want to introduce this evidence to show the possible bias of B as a witness.
Alaska Comm. R. Evid. 409