US SB3958

Transitions Puerto Rico from the current Nutrition Assistance Program block grant to full participation in the Supplemental Nutrition Assistance Program (SNAP), treating Puerto Rico as a state under the Food and Nutrition Act of 2008

Requires Puerto Rico to submit a transition plan within 180 days of designating a state agency, with the Secretary of Agriculture providing technical assistance and approving/rejecting the plan within 180 days

Establishes a 5-year implementation period during which the existing block grant may continue operating while Puerto Rico completes the transition to SNAP

Requires cost adjustments to the thrifty food plan to reflect Puerto Rico's actual food costs, similar to existing adjustments for Hawaii, Alaska, and Guam

Amendments take effect 10 years after enactment; authorizes appropriations as necessary through the transition period