CO-273: Service exceeds coverage program limits

The payer is saying the service went past what the benefit program allows. That could be too many units, too many days, the wrong setting for the diagnosis, or a frequency limit that has already been hit. On the back end the payer is reading your codes, units, dates, and sometimes diagnosis against its benefit rules and utilization flags. Anything beyond the allowed coverage window or quantity is carved off as a contractual adjustment, which you must write off unless you overturn the rule on appeal.

In behavioral health, CO-273 often appears when IOP or PHP days exceed the authorized span or plan maximum. Example: PHP per diem H0035 billed for 30 days when the prior authorization was approved for 20, so days 21 to 30 hit CO-273 and drop to zero. You also see this with outpatient therapy or psychiatry visits when a payer has a hard annual visit cap or requires step-down from residential before covering IOP. For instance, more than a set number of 90837 sessions per year, or weekly SUD group 90853 sessions beyond a program limit, may be cut with CO-273. Medicaid and MCO behavioral carve outs frequently use CO-273 when their program rules say a certain level of care is only covered for a defined episode length. Long residential SUD stays, extended detox, or continued OTP medication-only visits without required counseling can get partially denied under this code once their program limit is passed.

• Verify exactly what program or coverage rule was exceeded by checking the EOB, any attached RARC codes, and the payer portal.
• Compare the claim units, dates of service, and level of care to the prior authorization and to any visit or day caps on the member's plan.
• If you truly billed past the approved or allowed limit, rebuild the claim to only include covered days or units and submit a corrected claim.
• If the services fall within what was authorized but the payer applied the rule wrong, gather the auth letter, treatment notes, and utilization review records and submit an appeal.
• For facility per diem billing, move noncovered days to patient-responsibility status only if your payer contract and state rules clearly allow it, otherwise adjust them off.
• Track repeated CO-273 denials by payer and program so clinical and UR teams can adjust authorization requests and discharge planning and you can renegotiate limits in contracting.

• At admission and before each step-up or step-down, verify behavioral health benefits for visit caps, day limits, and level-of-care rules.
• Tie your scheduling and census tools to auth data so staff cannot book IOP, PHP, residential, or detox days beyond approved dates or quantities without a new authorization.
• Build claim-scrubber edits that flag charges when total days or visits for a member and CPT/HCPCS combo exceed the latest auth or known benefit maximum.
• Have UR staff request extensions early, document medical necessity clearly, and share updated approval spans with billing before final claims drop.