 [ Symptoms ] what is the cost of lantus solostar under medicare plan b [ Disease ] you pay a 147 deductible each year after you pay it you pay coinsurance which is 20 of your medical costs if you have medigap plan that 20 may be covered you pay a 147 deductible each year after you pay it you pay coinsurance which is 20 of your medical costs if you have a medigap plan it may help to cover that 20