Johnson (17-2-1) looks for his second 125-pound title defense in the main event of a UFC on Fox event Saturday at KeyArena. The bout will take place eight days after Johnson celebrated the birth of his first child -- a son, Tyren.
Both Johnson and Moraga (13-1) weighed in at 124.5 pounds.
All eight of the fighters scheduled to appear on Saturday's main card made weight; however, several undercard athletes struggled on the scale.
Late replacement Tim Means (18-4-1) weighed 160 pounds for his 155-pound fight against Danny Castillo (15-5). Bantamweight John Albert (7-4) weighed 137 for his bout against Yaotzin Meza (19-8). Each fighter forfeited a percentage of his purse.
Lightweight Jorge Masvidal (24-7), scheduled to face Michael Chiesa (9-0), came in at 157.5 pounds and was given two hours to cut to 156 by the Washington State Department of Licensing. He made weight on his second attempt.
In the co-main event, Rory MacDonald (14-1) will put a four-fight win streak on the line against Jake Ellenberger (29-6) in a high-profile welterweight contest. Ellenberger came in at the 171-pound limit; MacDonald weighed 170.5 pounds.