I'd do 5:15, but I go through the Clear line. Sometimes the pre-check line at National isn't that much shorter than the regular line.

5am if taking an Uber. 445 if you are driving.

Did this last week. 515

I'd get there at 4:30 at the latest. 5:15 Is too late

If taking a taxi/not parking and you have pre-check: 5:15; you're not checking a bag - you don't need to be the first person on the airplane.
If driving self, need to park, and don't have pre-check: no later than 4:45

If you're parking, aim to get there at 4:45. Getting dropped off - be there at 5. Source: someone who frequently takes 6 AM flights out of DCA.

5:15 if you have TSA pre-check and you checked in online.

The counters and such dont really open until 5, so there can be a rush then. I personally like to get there just before 5 for that 6am flight. Don't plan on getting coffee though, unless you beat the line!

Do you have TSA precheck?

Do you need to park or is someone dropping you off?

No way, 5:15 is not enough time considering boarding starts at 5:30 and doors close at 5:50.

What day of the week of it? Early morning security can be unpredictable, sometimes way more crowded than you'd expect with business travelers.

I personally wouldn't be comfortable getting there any later than 4:45, but I think 5 is at least better than 5:15.

I would be there no later than 5 just to account for possible security delays.

Thanks! Is 5;15 early enough?