The American Red Cross is rewarding new and previous donors who donate blood with e-gift cards because blood supply levels are critically low.

Donors of all blood types and platelets are needed, especially type O blood, according to a press release from the American Red Cross. The nonprofit stresses the importance of keeping the blood supply stable.

To schedule an appointment, visit RedCrossBlood.org, call 1-800-REDCROSS, or download the Red Cross Blood Donor App. A blood donor card, driver’s license or two other forms of identification are “needed to ensure a reliable supply for patients,” the release said.

The American Red Cross will show its appreciation to donors by giving them a $15 e-gift card if they donate by Sept 30, the press release said. Those who give between Oct. 1 through Oct. 30 will be thanked with a $10 Amazon.com gift card and will automatically be entered for a chance to win one of three $5,000 gift cards. For more information, please visit RedCrossBlood.org/Treat.

The American Red Cross “supplies about 40% of the nation’s blood,” the press release said. However, only 3% of Americans donate blood. The blood donated helps patients who need blood transfusions, including those in car accidents and those with sickle cell disease.