Forms received after that date are subject to a 90 day waiting period. Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization.ACERA will mail new members a Welcome Letter about 7 weeks after their start date that contains a link to complete our ACERA Welcome Form. Our next event is ______ and we cordially invite you to attend, and hope you will regularly participate in member activities in the future. Every ACERA member must fill out the ACERA Welcome Form. A "thank you for joining" membership letter should include a personalized greeting to the new member. Use the member's first name in your salutation. As a new Alliance Group Care member, we created handouts for you to learn more about your health plan, and your benefits and covered services. 1. Enter the date at the top of the letter. Welcome to Alameda County!