| $150,000–350,000 | M & M STRIPING & POWER WASHING, LLC | SAN ANTONIO, TX | Bank OZK |
| $350,000–1 million | M & M WEATHERIZATION COMPANY | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | M & P PRODUCE CO., INC. | SAN ANTONIO, TX | Wallis Bank |
| $1–2 million | M REZA MIZANI MD PA | SAN ANTONIO, TX | Zions Bank, A Division of |
| $350,000–1 million | M&M CONTRACTING, LTD | SAN ANTONIO, TX | Broadway National Bank |
| $350,000–1 million | M&S RADIOLOGY ASSOCIATES, P.A. | SAN ANTONIO, TX | BBVA USA |
| $150,000–350,000 | M. K. DAVIS RESTAURANT & BAR, LTD | SAN ANTONIO, TX | Frost Bank |
| $1–2 million | M. W. CUDE ENGINEERS, L.L.C. | SAN ANTONIO, TX | Vantage Bank Texas |
| $150,000–350,000 | M.E. ALLISON & CO., INC. | SAN ANTONIO, TX | Jefferson Bank |
| $350,000–1 million | M2 AMERICAN AUTO BROKERS LTD. | SAN ANTONIO, TX | The Bank of San Antonio |
| $350,000–1 million | M2 GLOBAL TECHNOLOGY, LTD | SAN ANTONIO, TX | Broadway National Bank |
| $350,000–1 million | M2 TECHNOLOGY, INC. | SAN ANTONIO, TX | Texas Capital Bank, National Association |
| $350,000–1 million | MACGREGOR MEDICAL CENTER SAN A | SAN ANTONIO, TX | Zions Bank, A Division of |
| $350,000–1 million | MACINA, BOSE, COPELAND, AND ASSOCIATES, INC. | SAN ANTONIO, TX | Jefferson Bank |
| $350,000–1 million | MACKENZIE RESTORATION, INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MADARADA INC | SAN ANTONIO, TX | City Bank |
| $150,000–350,000 | MADISON SQUARE PRESBYTERIAN CHURCH | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MADONNA NEIGHBORHOOD CENTERS, INC. | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MAESTAS & ASSOCIATES, LLC | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MAGENT, INC. | SAN ANTONIO, TX | First Bank of the Lake |
| $350,000–1 million | MAGI REALTY, INC | SAN ANTONIO, TX | International Bank of Commerce |
| $1–2 million | MAIN BUILDING MAINTENANCE, INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MAJOR INC. DBA RX TECHNOLOGY | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MAKHANI ENTERPRISES, INC | SAN ANTONIO, TX | Security State Bank & Trust |
| $150,000–350,000 | MALAISE LAW FIRM | SAN ANTONIO, TX | Broadway National Bank |
| $2–5 million | MALDONADO NURSERY & LANDSCAPING INC. | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MALE MEDICAL GROUP MANAGEMENT LLC | SAN ANTONIO, TX | International Bank of Commerce |
| $350,000–1 million | MALIKI LIKI ENTERPRISES LLC | SAN ANTONIO, TX | The Bank of San Antonio |
| $350,000–1 million | MALITZ CONSTRUCTION, INC. | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MALLEY & MALLEY L.P. | SAN ANTONIO, TX | Pioneer Bank, SSB |
| $350,000–1 million | MAMA MARGIE'S CULEBRA RD LTD | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MAMITA'S CUISINE, INC. | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MAN OF WIRE, INC | SAN ANTONIO, TX | Security Service FCU |
| $1–2 million | MANAGEMENT & BUSINESS ASSOCIATES INC | SAN ANTONIO, TX | Manufacturers and Traders Trust Company |
| $150,000–350,000 | MANAGEMENT GROUP USA LLC | SAN ANTONIO, TX | BBVA USA |
| $150,000–350,000 | MANGOLD ROOFING & SHEETMTL,INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MANI LITTLE & WORTMANN, PLLC | SAN ANTONIO, TX | Ciera Bank |
| $150,000–350,000 | MAPCO, INC. | SAN ANTONIO, TX | Truist Bank d/b/a Branch Banking & Trust Co |
| $150,000–350,000 | MARBROS LLC | SAN ANTONIO, TX | Bank of America, National Association |
| $350,000–1 million | MARENTCO, INC. | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MARICOPA PIZZA HOLDINGS LLC | SAN ANTONIO, TX | City National Bank of Florida |
| $150,000–350,000 | MARITO SPORTS CARS INC | SAN ANTONIO, TX | Zions Bank, A Division of |
| $150,000–350,000 | MARKETING EFFECTS, LLC. | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MARKSMEN GENERAL CONTRACTORS, LLC | SAN ANTONIO, TX | Broadway National Bank |
| $350,000–1 million | MARSH & ASSOCIATES, INC. ARCHITECTURE/PLANNING/INTERIORS | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MARTIN & DROUGHT, P.C. | SAN ANTONIO, TX | International Bank of Commerce |
| $150,000–350,000 | MARTINEZ & ASSOCIATES, PLLC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MASCOLA ESTHETICS DENTAL LAB LLC | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MASH'D SAN ANTONIO, LLC | SAN ANTONIO, TX | First United Bank and Trust Company |
| $150,000–350,000 | MASS MUTUAL SOUTH TEXAS | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MASSAGE HEIGHTS FRANCHISING, LLC | SAN ANTONIO, TX | Zions Bank, A Division of |
| $150,000–350,000 | MASSENGALE ARMATURE WORKS, INC. | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MASTER MARINE, INC. | SAN ANTONIO, TX | Community National Bank |
| $150,000–350,000 | MASTERS DENTAL GROUP, P.C. | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MATHIS CONSULTING SERVICES INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MATTRESSES FOR LESS LLC | SAN ANTONIO, TX | Security Service FCU |
| $150,000–350,000 | MAUZE CONSTRUCTION, CORP. | SAN ANTONIO, TX | Jefferson Bank |
| $350,000–1 million | MAVAGI ENTERPRISES INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MAVERICK EATS, LLC | SAN ANTONIO, TX | Broadway National Bank |
| $2–5 million | MAVERICK OF TEXAS CONSTRUCTION, INC | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MAVERICK UNDERGROUND INC | SAN ANTONIO, TX | American Express National Bank |
| $1–2 million | MAXMED HEALTHCARE INC | SAN ANTONIO, TX | JPMorgan Chase Bank, National Association |
| $150,000–350,000 | MAYA MAYA INC | SAN ANTONIO, TX | City Bank |
| $350,000–1 million | MAZUREK, BELDEN, & BURKE, P.C. | SAN ANTONIO, TX | Third Coast Bank SSB |
| $150,000–350,000 | MC BURGER, LLC | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MCA WESTOVER HILLS OPERATING COMPANY, LLC | SAN ANTONIO, TX | Fountainhead SBF LLC |
| $150,000–350,000 | MCC RESORT SAN ANTONIO LLC | SAN ANTONIO, TX | Truist Bank d/b/a Branch Banking & Trust Co |
| $350,000–1 million | MCCULLOUGH HALL NURSING HOME, INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MCDONALD'S | SAN ANTONIO, TX | The Bank of San Antonio |
| $350,000–1 million | MCDONALD'S BLANCO ROAD CORP | SAN ANTONIO, TX | Jefferson Bank |
| $350,000–1 million | MCDONALD'S GENERAL MCMULLEN CORP | SAN ANTONIO, TX | Jefferson Bank |
| $150,000–350,000 | MCDOUGAL PROPERTY MANAGEMENT LC | SAN ANTONIO, TX | Broadway National Bank |
| $350,000–1 million | MCDUFF ENTERPRISE LLC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MCJAM INC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MCNAIR CUSTOM HOMES LP | SAN ANTONIO, TX | The Bank of San Antonio |
| $350,000–1 million | MCNAY ART MUSEUM | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MD AUTOMOTIVE | SAN ANTONIO, TX | Wells Fargo Bank, National Association |
| $150,000–350,000 | MD BEVCO INC | SAN ANTONIO, TX | Lone Star National Bank |
| $150,000–350,000 | MD MANAGECO INC | SAN ANTONIO, TX | Lone Star National Bank |
| $350,000–1 million | MDS MAINTENANCE, LLC | SAN ANTONIO, TX | The Bank of San Antonio |
| $150,000–350,000 | MEADOWLAWN MEMORIAL PARK, INC. | SAN ANTONIO, TX | Citizens State Bank of Luling |
| $150,000–350,000 | MEADS CONSULTING AND CONTRACTING | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MEALS ON WHEELS SAN ANTONIO | SAN ANTONIO, TX | Broadway National Bank |
| $350,000–1 million | MECHANICAL REPS, INC. | SAN ANTONIO, TX | PlainsCapital Bank |
| $350,000–1 million | MED MANAGEMENT ASSOCIATES | SAN ANTONIO, TX | Zions Bank, A Division of |
| $1–2 million | MED SECURITY, INC. | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MEDCARE ASSOCIATES, P.A. | SAN ANTONIO, TX | International Bank of Commerce |
| $150,000–350,000 | MEDCEDE PHYSCIAN SERVICES, PLLC | SAN ANTONIO, TX | Zions Bank, A Division of |
| $150,000–350,000 | MEDIA DIGITAL SOURCE, LLC | SAN ANTONIO, TX | Broadway National Bank |
| $150,000–350,000 | MEDIA MOOLAH, LLC | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MEDICAL AND RADIATION PHYSICS INC. | SAN ANTONIO, TX | The Bank of San Antonio |
| $1–2 million | MEDICAL CENTER OPHTHALMOLOGY ASSOCIATES | SAN ANTONIO, TX | Frost Bank |
| $150,000–350,000 | MEDICAL CENTER PEDIATRICS | SAN ANTONIO, TX | BBVA USA |
| $150,000–350,000 | MEDICAL WHOLESALE, INC. | SAN ANTONIO, TX | Frost Bank |
| $350,000–1 million | MEDICAL-DENTAL-HOSPITAL BUREAU OF SAN ANTONIO, INC. | SAN ANTONIO, TX | The Bank of San Antonio |
| $150,000–350,000 | MEDINA GENERAL CONTRACTING LLC | SAN ANTONIO, TX | Celtic Bank Corporation |
| $150,000–350,000 | MEDITERRANEAN GRILL & KABOB INC | SAN ANTONIO, TX | Texas Community Bank |
| $150,000–350,000 | MEDVEIN MANAGMENT LLC | SAN ANTONIO, TX | Austin County State Bank |
| $150,000–350,000 | MEGA FURNITURE USA DISTRIBUTION LLC | SAN ANTONIO, TX | KS StateBank |
| $150,000–350,000 | MEINHARDT STABILIZING COMPANY, INC. | SAN ANTONIO, TX | Broadway National Bank |