CO-A6Contractual ObligationEligibility
CO-A6 Denial Code: Prior hospitalization / 30-day transfer rule not met
SNF-flavored denial: the qualifying prior hospitalization (3-day stay) or 30-day transfer requirement wasn't met before this admission.
Why CO-A6 happens
- ●SNF admission without a qualifying 3-day inpatient stay
- ●More than 30 days between hospital discharge and SNF admission
- ●Observation days mistaken for inpatient days
How to fix a CO-A6 denial
- 1
Verify the hospital stay's inpatient status and dates; appeal with records if the qualifying stay exists
- 2
If genuinely unqualified, discuss non-covered status with the family — notice rules apply
How to prevent it
Verify qualifying-stay criteria (inpatient status, day counts) at SNF pre-admission.
Drowning in CO-A6 denials?
OakClaim works every denial within 48 hours and builds prevention rules so they stop recurring.