Why do people keep saying the Coast Guard isn't part of the military?

While the US Coast Guard IS a part of the US Armed Services, they serve under the US Department of Transportation, NOT the Department of Defense. The USCG's primary duty is Law Enforcement, NOT military combat. This avoids the restrictions on the US Military enforcing CIVIL law (Posse Comitatus Act, 18 U.S.C. § 1385)

At one time it was not given the same status as the other military services and was not considered as one. That changed back in the mid to late 90s when the Coast Guard was officially designated and recognized as a military service and given the same status as that of any of the other military services. However in some people's mind that idea that they aren't probably still exists because of this and the fact that they are not aware of the full extent of the Coast Guard's role. While being deployed or TDY to Kuwait and Iraq I have personally seen members of the Coast Guard deployed to those regions for doing various maritime jobs at the sea port of Doha or on the Tigris River which runs through Iraq.

Because the US Military is governed under Title 10 of the US Code. The Coast guard is Title 14 of the US Code.

Not really a question per se.

There are 7 uniformed services.

There are 5 armed services.

There are 3 departments of the military.

The USCG falls under the first two.

In times of war, the USCG moves from DHS to DoD under the Department of the Navy.

In my adult lifetime i have seen the Coast guard go from the wimpy little step brother that was an after thought. To the massive dominant force it has become today. Back in the 80's it was only, Army, navy, air-force, Marines in all those little commercials and chants. Now the coast guard is included in it. I can understand why many would still have the old fashion attitude towards them. Unless one follows them they would not have known the growth over the last 20/30 years or so.

Technically they are, but during peacetime they're not under the Defense Department.