An insurer may impose a pre-existing condition exclusion only if:
1. The exclusion relates to a condition, regardless of the cause of the condition, for which medical diagnosis, care, or treatment was recommended or received within the six-month period ending on the effective date of the person's coverage.
2. The exclusion extends for a period of not more than twelve months after the effective date of coverage. A group policy may impose an eighteen-month pre-existing condition to a late enrollee, as the term late enrollee is defined in section 26.1-36.3-01.