For the 2019 Kia Optima, headlight bulb fitment depends on the headlight type. Models with halogen headlights use a 9005 bulb for both the low beam and high beam. Models equipped with LED headlights use LED lighting for both functions.
The fog lights, daytime running lights, parking lights, and center stop light are also LED. Front turn signals use 2357A bulbs, while rear turn signals use 1156A. Reverse lights use 921 bulbs.
Brake and rear-light fitment varies with the headlights: halogen-equipped models use 7528 for the brake light, while LED-headlight models use LED brake lighting. Rear tail-light listings include 2825, 98, LED, and 7528, depending on the specified application. Front side markers use 2825 or 98; rear side markers use 2825 or 98 with halogen headlights and LED with LED headlights. License-plate lights use 2825 or 98.
Interior listings include 6461 for the dome light, 6418 for the glove box, trunk, and vanity lights, and 194 or 7441 for map lights.