; and (2) by adding at the end the following new clause: (iii) the differences in flood risk for properties located in coastal areas and properties located inland; and . (b) Establishment of chargeable premium rates Paragraph (1) of section 1308(b) of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4015(b)(1) ) is amended by inserting due to differences in flood risk for properties located in coastal areas and properties located inland and after including differences in risks . (c) Revised rates Not later than the expiration of the two-year period beginning on the date of the enactment of this Act, the Administrator of the Federal Emergency Management Agency shall revise risk premium rates under the National Flood Insurance Program to implement the amendments made by this section. 105. Monthly installment payment of premiums Subsection (g) of section 1308 of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4015(g) ) is amended— (1) by striking the subsection designation and all that follows through With respect and inserting the following: (g) Frequency of premium collection (1) Options With respect