The making of a declaration pursuant to this chapter does not affect the sale, procurement, or issuance of a policy of life insurance or annuity, nor does it affect, impair, or modify the terms of an existing policy of life insurance or annuity. A policy of life insurance or annuity is not legally impaired or invalidated by the withdrawal or withholding of life-sustaining treatment from an insured, notwithstanding any term to the contrary.
SDCL 34-12D-15