As a general rule, "[a] party to a contract may waive performance of any provision of the contract that is for its benefit." South Lake Center v. Waker Associates, Inc., 129 Or App 581, 589, 879 P2d 1342 (1994). In the context of an insurance contract specifically, "[c]onduct of an insurer after a loss has occurred that is inconsistent with a particular defense, especially where the insured has been * * * led to believe there is coverage, will constitute a waiver of the defense."
Under contract law, "[a] party to a contract may waive performance of any provision of the contract that is for its benefit." South Lake Center v. Waker Assocs., Inc., 129 Or App 581, 589, 879 P2d 1342 (1994). Even though a contract may require all modifications to the contract to be in writing, a waiver of a provision in the contract need not be in writing.