Improving Care and Access to Nurses Act or the I CAN Act This bill allows other health care providers besides physicians (e.g., nurses) to provide certain services under Medicare and Medicaid. Among other changes, the bill (1) allows a nurse practitioner or physician assistant to fulfill documentation requirements for Medicare coverage of special shoes for diabetic individuals; (2) expedites the ability of physician assistants, nurse practitioners, and clinical nurse specialists to supervise Medicare cardiac, intensive cardiac, and pulmonary rehabilitation programs; and (3) allows nurse practitioners to certify the need for inpatient hospital services under Medicare and Medicaid.