| Upper Level (Tracks 1–2)[1] | Northbound | ←  A Line toward Azusa (Chinatown)
|
| Island platform, doors will open on the left | ||
| Southbound | A Line toward Long Beach (Little Tokyo/Arts District) →
| |
| Upper Level (Tracks 3–15) | Track 3 | under construction |
| Island platform, closed | ||
| Track 4 | closed | |
| Track 5 | closed | |
| Island platform, doors will open on the left or right | ||
| Eastbound | Riverside Line toward Riverside–Downtown (Montebello/Commerce) → | |
| Eastbound | San Bernardino Line toward San Bernardino–Downtown (Cal State L.A.) → | |
| Island platform, doors will open on the left or right | ||
| Northbound | Ventura County Line toward Ventura–East (Glendale) → Antelope Valley Line toward Lancaster (Glendale) → | |
| Northbound | Coast Starlight toward Seattle (Hollywood Burbank Airport) → Pacific Surfliner toward San Luis Obispo (Glendale) → | |
| Island platform, doors will open on the left or right | ||
| Eastbound | Southwest Chief toward Chicago (Fullerton) → | |
| Eastbound | Sunset Limited toward New Orleans (Pomona) → Texas Eagle toward Chicago via San Antonio (Pomona) → | |
| Island platform, doors will open on the left or right | ||
| Southbound | Pacific Surfliner toward San Diego (Fullerton) → | |
| Eastbound | Orange County Line toward Oceanside (Norwalk/Santa Fe Springs) → Orange County Line toward Oceanside (Commerce (limited)) → | |
| Island platform, doors will open on the left or right | ||
| Southbound | 91/Perris Valley Line toward Perris–South (Norwalk/Santa Fe Springs) → | |
| Track 15 | Metrolink overflow | |
| Side platform, doors will open on the left or right, no access from passageway | ||
| Upper Level (Bus Platform) | Eastbound |  J Line toward El Monte (LA General Medical Center) →
|
| Island platform, doors will open on the right | ||
| Westbound | ← J Line toward Harbor Gateway or San Pedro (Los Angeles St)
| |
| Passageway | Entrance/exit, Ticket machines, Patsaouras Transit Plaza, Historic station | |
| Lower Level | Northbound/ Westbound |
←  B Line toward North Hollywood (Civic Center/Grand Park)←  D Line toward Wilshire/Western (Civic Center/Grand Park)
|
| Island platform, doors will open on the left or right | ||
| Northbound/ Westbound |
← B Line toward North Hollywood (Civic Center/Grand Park) ← D Line toward Wilshire/Western (Civic Center/Grand Park)
| |
- ^ "Union Station layout map" (PDF). Los Angeles County Metropolitan Transportation Authority. November 2022. Retrieved June 12, 2023.