Del. Code tit. 18 § 6101
Unless approval is granted pursuant to § 6102 of this title, no insurer may rescind, cancel or limit any health insurance policy, contract, evidence of coverage or certificate that provides coverage of the types specified in § 6103 of this title on the basis of written information submitted on, with or omitted from an insurance application by the insured if the insurer failed to complete medical underwriting and resolve all reasonable medical questions related to the written information submitted on, with or omitted from the insurance application before issuing the policy, contract, evidence of coverage or certificate. No insurer may rescind, cancel or limit any such health insurance policy, contract, evidence of coverage or certificate once the enrollee is covered under such plan or coverage involved, except this section shall not apply to a covered individual who has performed an act or practice that constitutes fraud or who makes an intentional misrepresentation of a material fact, as prohibited by the terms of the plan or coverage, and such omission materially affects the risk or the hazard assumed by the insurer or health care center. Such plan or coverage may not be cancelled except with prior notice to the enrollee, and except as permitted under applicable federal, state or local laws.
18 Del. C. § 6101