A regular full-time civilian employee of the Alaska Army National Guard and Air National Guard whose entire salary is paid from allotted federal funds is included in the public employees' defined contribution retirement plan (AS 39.35.700 - 39.35.990) if the federal or state government pays the employer's contributions. If the amount that the federal government may legally contribute to the plan is lower than the required employer's contribution, the state government shall contribute the difference. If the employer's contributions are not paid when due, service credit for the period of delinquency may not be granted until the contributions are paid.