SPD wording states coverage will begin first of the month following 45 days as an Active Employee. Employee was out on disability for 11 days during the waiting period. Would his effective date then be moved up an additional month?

If the plan is a health plan subject to HIPAA nondiscrimination rules, you can't apply "actively at work" requirements other than the requirement that an individul begin work for the employer sponsoring the plan. (So, if the employee came to work for a day and then was disabled, coverage must be available at the same time as it would be if the employee was not disabled.)