The "Main Street Capital Access Act" seeks to improve federal banking laws by fostering new bank formation, tailoring regulations, and enhancing supervisory transparency and accountability. Title I promotes new bank formation by establishing a three-year phase-in period for capital standards and streamlining business plan changes for new depository institutions. It also lowers the Community Bank Leverage Ratio for rural institutions and mandates studies on the causes of low de novo bank formation and methods to revitalize rural depositories. This title further requires federal agencies to publish annual reports detailing charter application numbers, approval times, and reasons for denial or withdrawal. It sets strict 90-day deadlines for agency decisions on bank and holding company applications, with applications deemed approved if deadlines are missed, and clarifies that only applicant-provided information can be used to determine application completeness. Title II focuses on tailoring bank regulation by requiring federal financial institutions regulatory agencies to consider the risk profiles and business models of institutions when issuing new regulations, and to conduct a look-back review of existing regulations. It raises the asset threshold for small bank holding company relief to $25 billion and increases the Community Bank Leverage Ratio asset threshold to $15 billion, adjusting the ratio range to between 6 and 8 percent. Additionally, various regulatory thresholds are indexed to account for increases in current-dollar United States Gross Domestic Product, with periodic adjustments every five years. Title III aims for fair and transparent bank supervision by amending the CAMELS rating system to establish clear, objective criteria and either eliminate or revise the management component. It sets deadlines for completing examinations and providing final reports, and establishes a process for financial institutions to request written guidance from regulators. A significant provision creates an Office of Independent Examination Review within the Federal Financial Institutions Examination Council to investigate complaints and provide independent review of material supervisory determinations, with a right to judicial review. This title also provides examination relief for well-managed and well-capitalized institutions with less than $6 billion in assets, allowing for alternating limited-scope examinations and combined examinations. It mandates that the Federal Reserve establish transparent models and assumptions for stress tests, publicly disclose scenarios, and prohibits climate-related stress tests for nonbank financial companies. Furthermore, it requires a Federal Reserve Board member with community bank experience to oversee supervision of smaller banking organizations and prohibits federal banking agencies from using "reputational risk" in supervision or enforcement actions. Title IV enhances regulatory accountability and transparency by restructuring the FDIC Board to include members with state bank supervisory and community bank experience, and limits board terms. It mandates that all agency guidance include a "guidance clarity statement" indicating it is not legally binding. The Economic Growth and Regulatory Paperwork Reduction Act is amended to require regulatory reviews every seven years, including internal assessments of cumulative regulatory impact. Title V strengthens local bank funding by increasing the amount of reciprocal deposits that are not considered brokered deposits, based on a tiered asset size, and modifies the agent institution rating requirement. It also creates a limited exception for certain custodial deposits from being classified as brokered deposits for eligible institutions under $10 billion, with interest rate restrictions if the institution is not well-capitalized. The Federal Reserve is also required to review and modernize its discount window operations, addressing technology, stigma, and access. Title VI promotes bank competition and merger clarity by exempting merger transactions resulting in institutions with less than $10 billion in assets from certain antitrust considerations, with this threshold indexed to GDP. It also mandates a GAO study and triennial Inspector General reviews of federal agencies' merger review procedures, focusing on timeliness, efficiency, and impact. Finally, Title VII strengthens transparency in bank resolutions by allowing the FDIC a "least cost resolution exception" to prioritize limiting concentration in global systemically important banks, even if it's not the absolute least costly option. Title VIII facilitates innovation and bank partnerships by modernizing merchant banking rules to extend investment holding periods to 15 years and requiring studies on the impact of bank and credit union partnerships with financial technology companies.