The "Investing in Community Resilience Act of 2025" amends the Robert T. Stafford Disaster Relief and Emergency Assistance Act to significantly expand the types of activities eligible for disaster assistance. It explicitly adds "preparedness" to the list of disaster relief efforts and includes programs that demonstrate substantial, science-based, and verified increased resilience from building standards or land use practices against various disasters like storms, floods, and wildfires. Furthermore, the bill introduces support for viable community emergency response teams or equivalent non-governmental organizations that provide disaster assistance, encouraging regular training, outreach, and participation in preparedness exercises. The Federal Emergency Management Agency (FEMA) is mandated to issue comprehensive guidance to State and Tribal governments on these new measures within one year of enactment. The Act will take effect one year after its enactment and will be carried out using only funds appropriated to FEMA, without authorizing additional appropriations.