A. Each group accident and sickness insurance policy shall contain a provision that written proof of the loss shall be furnished to the insurer within ninety days after the date of the loss. In the case of a claim for loss of time for disability, each group accident and sickness insurance policy shall contain a provision that written proof of the loss shall be furnished to the insurer within ninety days after the commencement of the period for which the insurer is liable. Subsequent written proof of the continuance of the disability shall be furnished to the insurer at reasonable intervals required by the insurer.
B. Failure to furnish such proof within the prescribed time shall not invalidate or reduce any claim if it was not reasonably possible to furnish the proof within that time and the proof is furnished as soon as reasonably possible. In no event, except in the absence of legal capacity of the claimant, shall such proof be furnished later than one year from the time proof is otherwise required.