S.3427: A bill to amend the Internal Revenue Code of 1986 to provide a credit for hurricane mitigation expenditures, and to provide a credit for the increased insurance premiums of certain homeowners as a result of hurricane events.

Costal [sic] Homeowners Assistance Act - Amends the Internal Revenue Code to allow tax credits for: (1) 25% of the qualified hurricane mitigation property expenditures incurred by a homeowner in a federally declared hurricane disaster area or in a county located in a state which borders the Atlantic Ocean or the Gulf of Mexico, up to $5,000; and (2) 50% of the increases in homeowner insurance premiums in such disaster areas, up to $5,000. Includes within the definition of "qualified hurricane mitigation property expenditures" expenditures to improve the strength of a roof deck attachment, create a secondary water barrier, improve the durability of a roof covering, or protect exterior doors and garages.