Does Medicare Part B Cover Lab Work? 
Medicare Part B covers virtually all outpatient expenses including doctor visits , X-ray , MRI , CT , outpatient surgery , ER , ambulance and lab work . Part B has an annual deductible of $ 147 -LRB- for 2013 -RRB- and then Medicare pays 80 % of approved charges , you pay the remaining balance . If you have a Medigap plan your liability may be $ 0 if you have plan F 