The 28-year-old Oberg made $555,000 in 2018 as he emerged as one of Colorado's more reliable relievers. He was 8-1 with a 2.45 ERA and 57 strikeouts over 58 2/3 innings.
Oberg appeared in all four of Colorado's postseason games last season, posting a 1-0 record with a 4.91 ERA.
He spent some time on the disabled list last June with a strained back. He also was on the paternity list from Aug. 14-17.
Oberg was taken by Colorado in the 15th round of the 2012 amateur draft.