This bill, titled the "Infertility Treatment Affordability Act of 2025," amends the Internal Revenue Code of 1986 to introduce a new income tax credit. This credit is designed to help individuals manage the costs associated with infertility treatments, allowing an eligible individual to claim 50 percent of their qualified infertility treatment expenses paid or incurred during a taxable year. The credit is subject to several limitations, including an overall dollar cap and an income-based reduction for higher earners. Notably, up to $5,000 of the credit is refundable, meaning taxpayers can receive it even if it exceeds their tax liability, with this amount subject to inflation adjustments after 2025. To prevent double benefits, the credit cannot be claimed for expenses reimbursed by insurance or other government programs, or for expenses already used for other tax deductions or credits. "Qualified infertility treatment expenses" cover costs for treatments provided by licensed medical professionals following an infertility diagnosis. Crucially, it also includes expenses for fertility preservation procedures undertaken before medical treatments that a physician determines may cause involuntary infertility, even if an infertility diagnosis has not yet occurred. The bill defines "infertility" to include iatrogenic infertility but excludes procedures designed for sterilization. An "eligible individual" is someone diagnosed with infertility or determined to need fertility preservation due to impending medical procedures. Unused credit amounts can be carried forward for up to five subsequent taxable years.