Section 489.31 - Allowable charges: Blood(a)Limitations on charges.(1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red cells furnished under Medicare Part A during a calendar year, or furnished under Medicare Part B during a calendar year.(2) The charges may not exceed the provider's customary charges.(3) The provider may not charge for any whole blood or packed red cells in any of the circumstances specified in § 409.87(c)(2) of this chapter.(b)Offset for excessive charges. If the charge exceeds the cost to the provider, that excess will be deducted from any Medicare payments due the provider.56 FR 23022, May 20, 1991, as amended at 57 FR 36018, Aug. 12, 1992