Federal Deposit Insurance Improvement Act of 1991

Federal Deposit Insurance Improvement Act of 1991 - Amends the Federal Deposit Insurance Act and the Federal Credit Union Act to require the Federal Deposit Insurance Corporation (FDIC) and the National Credit Union Administration Board (NCUAB) to establish: (1) criteria for ascertaining the degree to which an insured depository institution poses a risk to the Bank Insurance Fund, the Savings Association Insurance Fund, or the National Credit Union Share Insurance Fund; and (2) assessment categories for their respective members based upon the types and degree of risk posed by members to the respective insurance fund. Mandates that the appropriate body establish separate rates for each assessment category. Authorizes the FDIC and the NCUAB to allocate aggregate assessment credits among such assessment categories.

Directs the FDIC and the NCUAB to: (1) insure those deposits at an insured depository institution for which the depositor has elected insurance coverage and for which insurance premiums have been paid; and (2) establish procedures for the mandatory periodic disclosure by their members to depositors of current assessment rates, and the amount of insurance coverage which depositors may elect.

Provides for depositor copayment of one third of the depository institution's cost for insurance coverage elected by the depositor.