Gaithersburg ZIP Codes & Area Codes: Complete Directory & Postal Map (MD)

Looking for a Gaithersburg ZIP code or trying to match a ZIP to its telephone area code? This directory maps the ZIP codes of Gaithersburg, Maryland, to their neighborhoods, counties, and the area codes that serve them. Use it to address mail correctly, verify a caller’s location, or understand how Gaithersburg’s postal and telephone geography line up.

Gaithersburg ZIP Codes & Area Codes at a Glance

Gaithersburg ZIP Code Directory

The table below lists major Gaithersburg ZIP codes with the neighborhood or district each covers, the telephone area code that serves it, and the county it falls in.

Beyond the neighborhoods listed above, Gaithersburg also has ZIP codes reserved for post-office boxes, large-volume business mailers, universities, and government facilities that do not correspond to a single residential district. When you are unsure which code to use, the USPS ZIP Code Lookup confirms the exact ZIP for any street address, while the area code shown in each row indicates the telephone prefix that most commonly serves that part of Gaithersburg. Mail sorted to the correct ZIP+4 moves faster and is less likely to be delayed or returned.

How Gaithersburg ZIP Codes and Area Codes Align

A ZIP code is a postal routing number, while an area code is a telephone routing number, so the two systems do not map one-to-one. In Gaithersburg, the 301, 240 area codes overlap the same territory that dozens of ZIP codes divide up. A single ZIP code can contain phone numbers from more than one area code, and a single area code spans many ZIP codes. For a full breakdown of the telephone side, see the Gaithersburg area code guide.

Because Maryland uses 10-digit dialing, always dial the area code plus the seven-digit number when calling a Gaithersburg line, even locally. When you only have a ZIP code, the directory above is the quickest way to see which area code most likely serves that part of the city.

Postal & Telecom Scam Warnings in Gaithersburg

Watch for fake home-services and rental-deposit scams, along with spoofed calls claiming to be from a local bank or utility. Across Gaithersburg ZIP codes, watch for USPS “undelivered package” smishing texts that ask you to pay a small redelivery fee, address-change and mail-hold fraud, and area-code spoofing that makes robocalls appear to come from a local Gaithersburg number. The Postal Service never texts you a payment link for a package, and legitimate callers do not demand gift cards or wire transfers. Report mail fraud to the U.S. Postal Inspection Service and unwanted calls to the FTC at reportfraud.ftc.gov.

Frequently Asked Questions

How many ZIP codes does Gaithersburg have?

Gaithersburg has approximately 3+ ZIP codes covering its neighborhoods and districts across Montgomery County.

What area codes serve Gaithersburg?

Gaithersburg is served by the 301, 240 area codes. See the Gaithersburg area code guide for full details.

Do ZIP codes and area codes match up in Gaithersburg?

Not exactly. ZIP codes route mail and area codes route calls, so one ZIP code can include more than one area code and each area code spans many ZIP codes. The directory above shows the most common pairing for each ZIP.

What is the main ZIP code for Gaithersburg?

Gaithersburg’s core ZIP codes are listed at the top of the directory table above; downtown and central neighborhoods usually carry the lowest-numbered ZIP codes in the city.

Are ZIP codes and area codes the same thing?

No. A ZIP code is a five-digit postal code used to route mail, while an area code is the three-digit prefix used to route telephone calls. Gaithersburg uses both systems, but they were designed independently and cover different-sized areas, which is why one ZIP code can overlap more than one area code.

What time zone is Gaithersburg in?

Gaithersburg observes Eastern Time (ET, UTC-5 / UTC-4).