All of the opening were on a Saturday and allowed free entry at the newly opening stations. Exceptions were the opening of the Blue line between National Airport and Stadium - Armory, it opened on a Friday with no free entry, Gallery Place upper level opened on a Wednesday with no free entry (after settling a lawsuit over the lack of handicap access), Phase I of the Silver line from East Falls Church to Wiehle - Reston East opened on a Saturday with no free entry at the newly opening stations, Phase II of the Silver line opened from Wiehle - Reston East to Ashburn on a Thursday with no free entry at the newly opening stations and Potomac Yard opened on a Friday with no free entry.
The mileage figures are based on end of platform to end of platform in each segment.
This list is more comprehensive then others posted elsewhere.
03 27 1976
| Metro Center (upper level) | Red |
| Farragut North | Red |
| Judiciary Square | Red |
| Union Station | Red |
| Rhode Island Avenue | Red |
5 Stations | 4.37 Miles 5 Stations |
12 15 1976
| Gallery Place (upper level) | Red |
| 1 Station | 6 Stations |
01 17 1977
| Dupont Circle | Red |
| 0.35 Miles 1 Station | 4.72 Miles 7 Stations |
07 01 1977
| Metro Center (lower level) | Blue |
| McPherson Square | Blue |
| Farragut West | Blue |
| Foggy Bottom - GWU | Blue |
| Rosslyn | Blue |
| Arlington Cemetery | Blue |
| Pentagon | Blue |
| Pentagon City | Blue |
| National Airport | Blue |
| Federal Triangle | Blue |
| Smithsonian | Blue |
| L'Enfant Plaza (lower level) | Blue |
| Federal Center SW | Blue |
| Capitol South | Blue |
| Eastern Market | Blue |
| Potomac Avenue | Blue |
| Stadium - Armory | Blue |
| 10.95 Miles 16 Stations | 15.68 Miles 23 Stations |
02 04 1978
| Brookland - CUA | Red |
| Fort Totten (upper level) | Red |
| Takoma | Red |
| Silver Spring | Red |
| 6.06 Miles 4 Stations | 21.75 Miles 27 Stations |
11 17 1978
| Minnesota Avenue | Orange |
| Deanwood | Orange |
| Cheverly | Orange |
| Landover | Orange |
| New Carrollton | Orange |
| 7.38 Miles 5 Stations | 29.13 Miles 32 Stations |
12 01 1979
| Court House | Orange | |
| Clarendon | Orange | |
| Virginia Square | Orange | |
| Ballston | Orange | |
| 2.58 Miles 4 Stations | 31.72 Miles 36 Stations |
11 22 1980
| Benning Road | Blue |
| Capitol Heights | Blue |
| Addison Road | Blue |
| 3.62 Miles 3 Stations | 35.35 Miles 39 Stations |
12 05 1981
| Woodley Park Zoo | Red |
| Cleveland Park | Red |
| Van Ness - UDC | Red |
| 2.48 Miles 3 Stations | 37.83 Miles 42 Stations |
04 30 1983
| Gallery Place (lower level) | Yellow |
| Archives | Yellow |
| L'Enfant Plaza (upper level) | Yellow |
| 3.20 Miles 2 Stations | 41.04 Miles 44 Stations |
12 17 1983
| Braddock Road | Yellow |
| King Street | Yellow |
| Eisenhower Avenue | Yellow |
| Huntington | Yellow |
| 4.89 Miles 4 Stations | 45.94 Miles 48 Stations |
08 24 1984
| Tenleytown - AU | Red |
| Friendship Heights | Red |
| Bethesda | Red |
| Medical Center | Red |
| Grosvenor | Red |
| 7.10 Miles 5 Stations | 53.04 Miles 53 Stations |
12 15 1984
| White Flint | Red |
| Twinbrook | Red |
| Rockville | Red |
| Shady Grove | Red |
| 6.97 Miles 4 Stations | 60.02 Miles 57 Stations |
06 07 1986
| East Falls Church | Orange |
| West Falls Church | Orange |
| Dunn Loring | Orange |
| Vienna | Orange |
| 9.45 Miles 4 Stations | 69.47 Miles 61 Stations |
11 22 1990
| Forest Glen | Red |
| Wheaton | Red |
| Miles 3.13 2 Stations | Miles 72.61 63 Stations |
05 11 1991
| Mount Vernon Square - UDC | Yellow |
| Shaw-Howard Univ | Yellow |
| U Street-Cardozo | Yellow |
| 1.52 Miles 3Stations | 74.14 Miles 66 Stations |
06 15 1991
| Van Dorn Street | Blue |
| 3.63 Miles 1 Station | 77.77 Miles 67 Stations |
12 28 1991
| Waterfront | Green |
| Navy Yard | Green |
| Anacostia | Green |
| 2.55 Miles 3 Stations | 80.33 Miles 70 Stations |
12 11 1993
| Fort Totten (lower level) | Green |
| West Hyattsville | Green |
| Prince George’s Plaza | Green |
| College Park - U of Md | Green |
| Greenbelt | Green |
| 7.61 Miles 4 Stations | 87.94 Miles 74 Stations |
06 28 1997
| Franconia - Springfield | Blue |
| 3.54 Miles 1 Station | 91.49 Miles 75 Stations |
07 25 1998
| Glenmont | Red |
| 1.70 Miles 1 Station | 93.19 Miles 76 Stations |
09 18 1999
| Columbia Heights | Green |
| Georgia Avenue - Petworth | Green |
| 3.30 Miles 2 Stations | 96.50 Miles 78 Stations |
01 13 2001
| Congress Heights | Green |
| Naylor Road | Green |
| Suitland | Green |
| Branch Avenue | Green |
| 6.62 Miles 4 Stations | 103.12 Miles 82 Stations |
11 20 2004
| New York Avenue - Gallaudet - U | Red |
| 1 Infill Station | 83 Stations |
12 18 2004
| Morgan Boulevard | Blue |
| Largo Town Center | Blue |
| 2.90 Miles 2 Stations | 106.03 Miles 85 Stations |
07 26 2014
| McLean | Silver |
| Tysons Corner | Silver |
| Greensboro | Silver |
| Spring Hill | Silver |
| Wiehle - Reston East | Silver |
| 11.49 Miles 5 Stations | 117.52 Miles 90 Stations |
11 15 2022
| Reston Town Center | Silver |
| Herndon | Silver |
| Innovation Center | Silver |
| Dulles Airport | Silver |
| Loudoun Gateway | Silver |
| Ashburn | Silver |
| 11.56 Miles 6 Stations | 129.08 Miles 96 Stations |
11 19 2023
| Potomac Yard | Blue |
| 1 Infill Station | 97 Stations |
Revised 07 20 2023.
