To amend the Federal Deposit Insurance Act to allow mutual capital certificates to satisfy capital requirements for mutual depositories.

Mutual Bank Capital Opportunity Act of 2017 This bill amends the Federal Deposit Insurance Act to allow mutual capital certificates issued by a mutual depository (i.e., a federally insured depository institution operating in a non-stock form) to qualify as common-equity Tier 1 capital for purposes of satisfying federal capital requirements. A "mutual capital certificate" is a financial instrument that: (1) is subordinate to all claims against, and unsecured by the assets of, the issuing mutual depository; (2) does not permit preemptive rights; (3) in general, does not provide voting or member rights; (4) is not eligible for use as collateral for any loan made by the issuing mutual depository; (5) entitles the holder to a payment of fixed, variable, or participating dividends (if the depository's board so declares); and (6) is generally not redeemable until five years after issuance. The appropriate federal banking agencies must jointly issue regulations to implement these provisions and to identify other financial instruments issued by mutual depositories that shall qualify as additional Tier 1 capital for purposes of federal capital requirements. The agencies must submit to Congress a series of reports on their progress in promulgating such regulations.