South Dakota legislators ended the session yesterday by overriding Gov. Daugaard's veto of a bill blocking insurance companies from offering policies that charge higher co-payments for visits to chiropractors than to primary care physicians. The legislation takes effect July 1. The Argus Leader reports Some insurance companies were charging a $50 or $60 co-pay for a chiropractor labeled as a specialist and $20 to $25 co-pay for a family doctor. The average cost of a routine chiropractor visit in South Dakota is $40.