Nurse Staffing Standards for Patient Safety and Quality Care Act of 2021 This bill requires hospitals to implement and submit to the Department of Health and Human Services (HHS) a staffing plan that complies with specified minimum nurse-to-patient ratios by unit. Hospitals must post a notice regarding nurse-to-patient ratios in each unit and maintain records of actual ratios for each shift in each unit. The bill also requires hospitals to follow certain procedures regarding how ratios are determined and other staff are prohibited from performing nurse functions unless specifically authorized within a state's scope of practice rules, among other requirements. HHS must adjust Medicare payments to hospitals to cover additional costs attributable to compliance with these ratios. Nurses may object to, or refuse to participate in, an assignment if it would violate minimum ratios or if they are not prepared by education or experience to fulfill the assignment without compromising the safety of a patient or jeopardizing their nurse's license. Hospitals may not (1) take adverse actions against a nurse based on the nurse's reasonable refusal to accept an assignment; or (2) discriminate against individuals for good faith complaints relating to the care, services, or conditions of the hospital or related facilities. HHS may impose civil monetary penalties on hospitals violating the ratio requirements and must publish the names of such hospitals. The bill provides stipends to the nurse workforce loan repayment and scholarship program and expands the nurse retention grant program to include nurse preceptorship and mentorship projects.