Providing Access to Treatment and Housing Act of 2023 or the PATH Act of 2023 This bill establishes a specific office and authorizes grants to support the provision of mental and behavioral health services for unhoused individuals. Specifically, the bill establishes the Center for Unhoused Individuals in the Substance Abuse and Mental Health Services Administration (SAMHSA). The center must develop policies and coordinate federal, state, and local action to expand unhoused individuals' access to mental, behavioral health, and housing services. The center may award grants to public and nonprofit entities to support these activities. SAMHSA must also award grants to state, local, and tribal governments to improve these services for unhoused individuals, with priority given to areas with high rates of housing instability and above-average housing costs.