Child Welfare Provider Inclusion Act of 2021 This bill generally prohibits the federal government, states, tribal nations, or localities from discriminating or taking adverse action against a child welfare provider that declines to provide services due to the provider's sincerely held religious beliefs or moral convictions. However, government entities may still take adverse action against a provider that declines to provide adoption or foster care services based on race, color, or national origin. The Department of Health and Human Services must withhold a portion of federal funding for family services and child welfare activities from a government entity that discriminates against a child welfare provider in violation of this bill. Child welfare providers may also sue the government entity for such discrimination. A prevailing provider may recover reasonable attorney's fees and costs. Furthermore, government entities that accept certain federal funding for family services and child welfare activities must waive sovereign immunity as a defense to lawsuits brought under this bill. (In many cases, sovereign immunity shields states, territories, tribal nations, and some localities against private suits.)