CO-108Contractual ObligationContractual
CO-108 Denial Code: Rent/purchase guidelines not met
DME rental or purchase rules weren't followed — e.g., billing purchase where the payer requires capped rental, or exceeding rental months.
Why CO-108 happens
- ●Rental billed past the cap (13 months for most Medicare DME)
- ●Purchase billed for an item the payer only rents (or vice versa)
How to fix a CO-108 denial
- 1
Check the item's payment category and rental history; rebill with correct modifiers (RR/NU/UE, KH/KI/KJ)
How to prevent it
DME billing software should track rental month counts per patient per item.
Drowning in CO-108 denials?
OakClaim works every denial within 48 hours and builds prevention rules so they stop recurring.