Opioid Patients' Right to Know Act of 2021 This bill requires the Centers for Disease Control and Prevention to award grants to states to educate health care providers about opioid prescribing practices. To receive a grant, a state must have a law or regulation that requires providers to, before issuing an initial opioid prescription to treat acute pain, inform patients about the risks of opioids and the availability of non-opioid treatment alternatives. States must use the grants to educate providers about relevant laws or regulations and safe opioid prescribing recommendations.