Capitalization of 'FM' in Street Addresses

In a U.S. street address, only the first letter of “FM” is capitalized (i.e., Fm or FM per local convention). Standard USPS formatting uses all caps for the entire address line, but the abbreviation itself is “FM” (Farm-to-Market road).

Examples

• Standard USPS (all caps): 123 MAIN ST FM 1234
• Mixed case: 123 Main St, FM 1234

Rule

“FM” stands for Farm-to-Market Road (Texas) or Farm Market (other states). It is a road designation, not a proper noun requiring internal capitalization. Treat as a standard abbreviation: capitalize both letters in all-caps addresses; otherwise, “Fm” or “FM” per style guide.

No need to capitalize the “M” separately if the rest is lowercase.