How can we help you? What is Competitive Bidding and how does that affect my Medicare power chair coverage? 2 out of 3 found this helpful Competitive Bid Areas (CBA) means that a contract is awarded to a power chair supplier based solely on price (not quality or service). If you live in one of these areas, this takes away your choices as a consumer and you will only be able to obtain a power chair from the bid winner. Was this helpful? Yes (2) No (0) Category: General Related Questions Do I have to pay the 20% co-payment? Why do I have to see a doctor for Medicare to cover my power wheelchair? Who initiates the necessary Medicare or insurance paperwork? What happens to my power chair if I go to a nursing home?