Middlefield Banc Corp. is an Ohio bank holding company whose sole operating subsidiary is The Middlefield Banking Company (MBC), an Ohio-chartered community bank founded in 1901. MBC takes in deposits and deploys them as loans to consumers, small and mid-sized businesses, and professionals across northeastern, central, and western Ohio through 21 branches across 12 counties. MBC's loan portfolio totals roughly $1.52B, with commercial real estate (~45%) and commercial & industrial loans (~15%) together accounting for about 60% of the book, making MBC predominantly a commercial lender. Residential real estate and home equity lines round out most of the remainder. About 70% of loans carry floating rates, so MBC's net interest margin is sensitive to rate movements. MBC funds its loans primarily through customer deposits (~$1.45B), supplemented by FHLB borrowings. MBC's strategy is to leverage a stable, low-cost deposit base in its rural Northeast and Western Ohio markets — where it holds strong share, including ~21% in Geauga County and ~35% in Hardin County — to fund loan growth in the higher-growth Columbus and Cleveland metro areas. MBC also earns modest non-interest income from mortgage banking, including gains on loans sold to Freddie Mac with servicing retained, and loan servicing fees. MBC argues it competes against larger banks through personal service, community relationships, and continuity of personnel.