Wisconsin Advances Major Breast Cancer Screening Coverage Bill

In a significant move to expand access to breast cancer detection and care, the Wisconsin Legislature has advanced 2025 Senate Bill 264, a bipartisan proposal to require broader insurance coverage for diagnostic and supplemental breast cancer screenings. The bill, introduced on May 20, 2025, strengthens existing state law to ensure that women—particularly those at higher risk or with dense breast tissue—have access to additional imaging and diagnostic services beyond standard mammograms.

Strong Bipartisan Support

Senate Bill 264 was introduced by a large coalition of senators—Cabral-Guevara, James, L. Johnson, Carpenter, Dassler-Alfheim, Drake, Habush Sinykin, Hesselbein, Keyeski, Larson, Nass, Ratcliff, Roys, Spreitzer, and Wall—and cosponsored by dozens of members of the Assembly. Throughout the legislative process, multiple lawmakers continued to sign on as coauthors and cosponsors, reflecting sweeping support.

The bill received its first reading on May 20, 2025, and was immediately referred to the Senate Committee on Health. A public hearing followed on May 28, 2025, and the Commissioner of Insurance submitted a report pursuant to Wisconsin Statute 601.423. A fiscal estimate was also received.

On June 2, 2025, the Committee on Health unanimously recommended passage, voting 5-0. The bill proceeded through scheduling and continued gaining sponsors through the summer. After a series of procedural steps—including adoption of Senate Amendment 1—the full Senate passed the bill on October 14, 2025, with a decisive vote of 32-1. The bill was then messaged to the Assembly for consideration, where additional representatives joined as cosponsors.

Key Provisions

Current Wisconsin law requires insurance policies to cover mammographic breast exams: two screening mammograms between ages 45 and 49, and annual mammograms beginning at age 50. Senate Bill 264 preserves these requirements while adding critical new protections.

Under the bill:

Health insurance policies and self-insured governmental health plans must cover diagnostic breast examinations.
These plans must also cover supplemental breast screening examinations for individuals at increased risk of breast cancer or those with heterogeneously or extremely dense breast tissue, as defined by nationally-recognized clinical standards.
Covered diagnostic and supplemental screenings include:
- Breast MRI
- Breast ultrasound
- Breast tomosynthesis
- Contrast-enhanced mammography
- Diagnostic mammography
- Other approved technologies consistent with the National Comprehensive Cancer Network guidelines

The bill explicitly defines each screening modality to ensure clarity and uniform application.

One of the most impactful components of the bill is its prohibition on cost-sharing for diagnostic or supplemental breast exams. Insurers may not impose deductibles, copayments, or other cost-sharing for these services, with a narrow exception designed to protect eligibility for Health Savings Accounts under federal law. For certain HSA-qualified high-deductible plans, the cost-sharing prohibition applies after the minimum IRS deductible is met, except for preventive services already exempt under federal guidance.

Medicaid Coverage Expansion

Senate Bill 264 also extends coverage to the state’s Medical Assistance program, ensuring supplemental and diagnostic breast screenings are accessible to low-income residents. This aligns the Medicaid program with private and public employer insurance requirements.

Implementation Timeline

If enacted, the bill would apply to insurance policy or plan years beginning January 1 following its effective date. For plans governed by collective bargaining agreements, the law would apply when those contracts are renewed or modified. The act would take effect on the first day of the fourth month after publication.

Wisconsin’s 2025 Senate Bill 264 represents a bipartisan effort to modernize breast cancer screening policy, increase early detection, and remove financial barriers to care. With overwhelming Senate approval and broad support across party lines, the measure marks a meaningful step in strengthening women’s health services across the state.