Your first payment, also known as the "binder payment," may be withdrawn anytime from the day you e-sign for your plan up until your start date. The good news is that once your payment is withdrawn, that means you’ve been approved! Your welcome packet and ID cards will follow in the mail within 14 business days after this initial deduction (most carriers quote a timeframe of 7 to 10 business days).
For ongoing months, most companies will charge you on/around the first day of the month for that month’s coverage. You can reach out to the carrier directly to set up auto-pay and choose which day each month you'd like for your premium to be deducted.