How can you cancel your bcbs?

Depends on whether you purchased the plan on your own or have the plan through an employer.

Employer purchased: You will need to have had a 'qualifying event'. Best thing to do is to contact your HR rep to find out more.

You purchased: BCBS will need to receive your request signed & in writing. Sometimes they might require a certain amount of days in advance notice of the cancellation, such as minimum 30 days for example. It's very, very rare that they will allow 'retro' terminations (going backward on the calendar to cancel on a date that has already passed). So be prepared well in advance & make sure you keep some kind of proof or receipt that they received your request (such as USPS certified mail receipt, fax confirmation sheet, etc.)