D.C. Code § 31-4802
If payment of such a policy shall be refused because of unsound health at or prior to the date of the policy, the good faith of both applicant and insured shall constitute a material element in determining the validity of the policy; and it shall not be held invalid because of unsound health unless the insurer shall prove that, at or before the date of issue of the policy, the insured or applicant had knowledge of, or reason to know, the facts on which the defense is based, or shall prove that the insurance was procured by the insured or applicant in bad faith or with intent to defraud the company, any provision, agreement, condition, warranty, or clause contained in said policy, or endorsed thereon, or added or attached thereto, to the contrary notwithstanding. Proof by the insurer of fraud, intent to deceive, unsound health, bad faith, breach of warranty or condition precedent, or other matter of defense, shall be subject to the provisions of § 31-5203.
D.C. Code § 31-4802
Formal requisites of insurance policies, see § 31-4703 et seq. .