The Obama administration says it wants to end discrimination against transgender people throughout the health care system.
The new protections are part of a much broader proposed regulation released Thursday by the Department of Health and Human Services.
The long-delayed rule amounts to a manual for carrying out the anti-discrimination section of President Barack Obama's health care law.
That law prohibits bias in medical care on the basis of race, color, national origin, sex, age, or disability. Those underlying provisions are in effect.
The latest proposal clarifies that gender identity is covered under the law's ban against sex discrimination.
Hospitals that accept Medicare would have to comply with the rule, as well as most doctors.
The rule doesn't require insurers to cover gender transition surgery.