AB400: Bill Text

2025 - 2026 LEGISLATURE

LRB-4270/1

KRP&JPC:skw

2025 ASSEMBLY BILL 400

August 29, 2025 - Introduced by Representatives Nedweski, Steffen, Allen, Behnke, Brill, Dittrich, Green, Knodl, Kreibich, Maxey, Murphy, Mursau, O'Connor, Penterman, Piwowarczyk and Wichgers, cosponsored by Senators Hutton, Kapenga, Bradley and Nass. Referred to Committee on Judiciary.

AB400,1,2 An Act to create 895.039 of the statutes; relating to: a civil cause of action for a minor injured by a gender transition procedure.

Analysis by the Legislative Reference Bureau

This bill establishes a civil cause of action against a health care provider who performs a gender transition procedure, as defined in the bill, on an individual who is under 18 years of age and who is injured, including any physical, psychological, emotional, or physiological injury, by the gender transition procedure or related treatment or the aftereffects of the gender transition procedure or related treatment. Under the bill, such an action must be commenced before the individual attains the age of 33 years.

The bill provides that it is a defense to an action under the bill if all of the following occur before a health care provider performs a gender transition procedure on an individual who is under 18 years of age:

1. The health care provider documents the individual’s perceived gender or perceived sex for at least two continuous years, and the individual’s perceived gender or perceived sex is invariably inconsistent with the individual’s biological sex throughout the two-year period.

2. To the extent that the individual suffers from a mental health concern, at least one mental health professional and one other health care provider certifies in writing that the gender transition procedure is the only way to treat the mental health concern.

3. At least one mental health professional and one other health care provider certifies in writing that the individual suffers from no other mental health concerns.

4. The health care provider receives the voluntary and informed consent of the individual and the individual’s parent or legal guardian by providing them, both orally and in writing, with a notice, the contents are which are prescribed in the bill, at least 30 days before the first treatment of the gender transition procedure and during every subsequent medical visit for treatment during the following six months.

The people of the state of Wisconsin, represented in senate and assembly, do enact as follows:

AB400,1 Section 1. 895.039 of the statutes is created to read:

AB400,2,3 895.039 Performing gender transition procedures on minors; liability. (1) Definitions. In this section:

AB400,2,6 (a) 1. “Gender transition procedure” means a medical or surgical service, including a physician’s service, inpatient or outpatient hospital service, or prescribed drug, related to gender transition that seeks to do any of the following:

AB400,2,8 a. Alter or remove an individual’s physical or anatomical characteristics or features that are typical for the individual’s biological sex.

AB400,2,15 b. Instill or create for an individual physiological or anatomical characteristics that resemble a sex different from the individual’s biological sex, including a medical service that provides puberty-blocking drugs, cross-sex hormones, or another mechanism to promote the development of feminizing or masculinizing features in a sex different from the individual’s biological sex, or genital or nongenital gender reassignment surgery performed for the purpose of assisting an individual with a gender transition.

AB400,3,2 2. Notwithstanding subd. 1., “gender transition procedure” does not include any of the following:

AB400,3,7 a. A service provided to an individual born with a medically verifiable disorder of sexual development, including an individual with external biological sex characteristics that are irresolvably ambiguous, such as an individual born with 46,XX chromosomes with virilization, with 46,XY chromosomes with undervirilization, or having both ovarian and testicular tissue.

AB400,3,12 b. A service provided to an individual when a physician has diagnosed a sexual development disorder and the physician has determined through genetic or biochemical testing that the individual does not have the normal sex chromosome structure, sex steroid hormone production, or sex steroid hormone action for a biological male or biological female.

AB400,3,16 c. The treatment of an infection, injury, disease, or disorder that is caused or exacerbated by the performance of a gender transition procedure, regardless of whether the gender transition procedure was performed in accordance with state or federal law.

AB400,3,20 d. A procedure undertaken because an individual suffers from a physical disorder, physical injury, or physical illness that would, as certified by a physician, place the individual in imminent danger of death or impairment of major bodily function unless surgery is performed.

AB400,3,21 (b) “Health care provider” has the meaning given in s. 146.81 (1) (a) to (hp).

AB400,3,22 (c) “Mental health professional” means any of the following:

AB400,4,2 1. A physician licensed under subch. II of ch. 448 who specializes in psychiatry.

AB400,4,3 2. A psychologist licensed under ch. 455.

AB400,4,4 3. A professional counselor licensed under ch. 457.

AB400,4,5 4. A marriage and family therapist licensed under ch. 457.

AB400,4,6 5. A social worker certified or licensed under ch. 457.

AB400,4,7 (d) “Minor” means an individual who is under 18 years of age.

AB400,4,14 (2) Civil causes of action. A health care provider who performs a gender transition procedure on a minor is liable to the minor if the minor is injured, including any physical, psychological, emotional, or physiological injury, by the gender transition procedure or related treatment or the aftereffects of the gender transition procedure or related treatment. The minor, or the minor’s parent, legal guardian, or legal representative, may bring a civil action against the health care provider for any of the following damages:

AB400,4,15 (a) Declaratory or injunctive relief.

AB400,4,16 (b) Compensatory damages.

AB400,4,17 (c) Punitive damages.

AB400,4,18 (d) If the prevailing party, reasonable attorney fees and costs.

AB400,4,22 (3) Limitation of actions. An action under this section shall be commenced before the minor has attained the age of 33 years or, if the minor dies before attaining the age of 33 years, the date on which the minor would have attained the age of 33 years.

AB400,5,2 (4) Safe harbor. (a) It is a defense to an action brought under this section if, before a health care provider performs a gender transition procedure on a minor, all of the following occur:

AB400,5,6 1. The health care provider documents the minor’s perceived gender or perceived sex for at least 2 continuous years, and the minor’s perceived gender or perceived sex is invariably inconsistent with the minor’s biological sex throughout the 2-year period.

AB400,5,10 2. To the extent that the minor suffers from a mental health concern, at least 2 health care providers, including at least one mental health professional, certifies in writing that the gender transition procedure is the only way to treat the mental health concern.

AB400,5,15 3. At least 2 health care providers, including at least one mental health professional, certifies in writing that the minor suffers from no mental health concerns other than the concern described under subd. 2., including depression, an eating disorder, autism, attention deficit hyperactivity disorder, intellectual disability, or a psychotic disorder.

AB400,5,17 4. The health care provider receives the voluntary and informed consent of the minor and the minor’s parent or legal guardian as provided in par. (b).

AB400,5,23 (b) Consent to a gender transition procedure is voluntary and informed under par. (a) 4. only if, at least 30 days before the first treatment of the gender transition procedure and during every subsequent medical visit for treatment during the following 6 months, the minor and the minor’s parent or legal guardian is provided with the following notice, both orally and in writing in at least 14-point type in a proportional font:

AB400,6,1 NOTICE

AB400,6,8 If your child begins one of these treatments, it may actually worsen the discordance and thus increase the likelihood that your child will need additional and more serious interventions to address the worsening condition. For example, if your child begins socially transitioning or taking puberty blockers, that treatment may significantly increase the likelihood that your child’s discordance will worsen and lead to your child eventually seeking cross-sex hormones or even surgery to remove some of your child’s body parts.

AB400,6,12 Sweden, Finland, and the United Kingdom have conducted systematic reviews of evidence and concluded that there is no evidence that the potential benefits of puberty blockers and cross-sex hormones for this purpose outweigh the known or assumed risks.

AB400,6,17 Medical authorities in Sweden, Finland, and the United Kingdom have since recommended psychotherapy as the first line of treatment for youth gender dysphoria, with drugs and surgeries reserved as a measure of last resort. Medical authorities in France have advised “great caution” when prescribing hormones for gender dysphoria.

AB400,6,23 There are people who underwent gender transition treatments as minors and later regretted that decision and the physical harm that these treatments caused, and the total percentage of people who experience this regret is unknown. Some estimate that the rate is below 2 percent, but that estimate is based on studies done on adults who transitioned as adults or on minors who transitioned under highly restrictive and controlled conditions.

AB400,7,7 Sometimes gender transition treatments have been proposed as a way to reduce the chances of a minor committing suicide due to discordance between the minor’s sex and his or her perception, but the rates of actual suicide from this discordance remain extremely low. Furthermore, as recognized by health authorities in Europe, there is no evidence that suicidality is caused by “unaffirmed” gender or that gender transition treatments are causally linked to a reduction in serious suicidal attempts or ideations.

AB400,7,8 For puberty blockers:

AB400,8,2 Puberty blockers are not approved for this purpose by the U.S. food and drug administration, which is the federal agency that determines which drugs are safe and effective for humans to use. Claims about puberty blockers’ safety and efficacy are based on their use for precocious puberty, a different condition in which normal puberty is allowed to resume once the patient reaches the appropriate age. Studies on the benefits of using puberty blockers for gender dysphoria are notoriously weak. Puberty blockers are not fully reversible because, among other risks, puberty blockers may intensify a minor’s discordance and cause it to persist. Puberty blockers increase the risk of your child being sterilized, meaning that he or she will never be able to have children. Puberty blockers may also cause diminished bone density for your child, increasing the risk of fracture and early osteoporosis. Puberty blockers may also prevent your child from ever being able to engage in sexual activity or achieve orgasm for the rest of your child’s life. There is no research on the long-term risks to minors of persistent exposure to puberty blockers. The full effects of puberty blockers on brain development and cognition are unknown.

AB400,8,3 For cross-sex hormones:

AB400,8,17 The use of cross-sex hormones in males is associated with numerous health risks, such as thromboembolic disease, including blood clots; cholelithiasis, including gallstones; coronary artery disease, including heart attacks; macroprolactinoma, which is a tumor of the pituitary gland; cerebrovascular disease, including stroke; hypertriglyceridemia, which is an elevated level of triglycerides in the blood; breast cancer; and irreversible infertility. The use of cross-sex hormones in females is associated with risks of erythrocytosis, which is an increase in red blood cells; severe liver dysfunction; coronary artery disease, including heart attack; hypertension; and increased risk of breast and uterine cancer. Once a minor begins cross-sex hormones, the minor may need to continue taking those hormones for many years and possibly for the remainder of the minor’s life. The cost of these hormones may be tens of thousands of dollars. If the use of cross-sex hormones leads to surgery, the total cost of transitioning may exceed $100,000.

AB400,8,18 For surgical procedures: