What does CO-222 mean?

CO-222 is a Contractual Obligation (CO) denial: "Exceeds the contracted maximum number of hours/days/units by this provider for this period. This is not patient specific." The provider billed more hours, days, or units in the period than the contract allows. The limit is at the PROVIDER level (not per patient), so the excess over the contracted maximum was denied.

CO · Contractual ObligationCARC 222

Denial Code CO-222

Q: Is CO-222 the patient's responsibility or a provider write-off?

CO-222 carries the CO group code (Contractual Obligation): Provider/contractual responsibility — not billable to the patient while denied. A CO adjustment is the provider's responsibility, not the patient's: balance-billing the patient for a CO amount is a contract (and often compliance) violation. But CO does not automatically mean “write it off.” When the cause is fixable — missing information (CO-16), a modifier problem (CO-4), or NCCI bundling (CO-97) — you correct and resubmit, or appeal with documentation. You only truly write the amount off when it is a final contractual adjustment, such as the fee-schedule difference on CO-45.

Exceeds the contracted maximum number of hours/days/units by this provider for this period. This is not patient specific.

Source: X12 Claim Adjustment Reason Codes (CARC) & Group Codes. Maintained by the D3rx Clinical Billing Team.

What CO-222 means

The provider billed more hours, days, or units in the period than the contract allows. The limit is at the PROVIDER level (not per patient), so the excess over the contracted maximum was denied.

Why CO-222 happens

Cumulative units/hours/days billed by the provider exceeded the contracted cap for the period
A contract-specific provider volume limit was reached
Multiple patients' services aggregated past the provider's contracted maximum
A keying or aggregation issue inflated the provider's period total

What to do when you get CO-222

1Locate the contracted maximum (hours/days/units per period) for this provider
2Confirm the period total actually exceeded the contracted cap
3If the cap was reached correctly, the excess isn't separately payable under the contract
4If the limit was misapplied or the total is wrong, appeal with the contract terms and corrected counts

Got this denial right now?

Ask D3 whether to appeal or correct CO-222

Ask D3 about CO-222 Ask D3 about CO-222

CO-222 can go either way depending on the claim. Ask D3 tells you whether to appeal, correct, or just confirm status — free.

CO group code: who absorbs the charge

Contractual Obligation — Provider/contractual responsibility — not billable to the patient while denied.

A CO adjustment is the provider's responsibility, not the patient's: balance-billing the patient for a CO amount is a contract (and often compliance) violation. But CO does not automatically mean “write it off.” When the cause is fixable — missing information (CO-16), a modifier problem (CO-4), or NCCI bundling (CO-97) — you correct and resubmit, or appeal with documentation. You only truly write the amount off when it is a final contractual adjustment, such as the fee-schedule difference on CO-45.

Appeal, correct, or write off CO-222?

CO-222 is a provider-level contract limit, not a patient or medical-necessity issue. Verify the contracted maximum and whether the period total genuinely exceeded it. Appeal only when the limit was misapplied or the aggregated total is incorrect — attach the contract terms and the accurate counts. A correctly applied contracted cap is a write-off, not an appealable denial.

Timing & deadlines

If appealing a misapplied limit, use the payer's window (commercial ~180 days from the remittance; Medicare 120 days for redetermination). There is no separate filing deadline for a correctly applied contractual cap.

Example

A provider's contract caps a service at a set number of units per month across all patients. Once the month's total exceeds that cap, additional units return CO-222. If the cap was reached correctly, the excess is a write-off; if the count is wrong, the contract supports an appeal.

Prevent CO-222 going forward

Track contracted period maximums (hours/days/units) at the provider level
Monitor cumulative volume against the contracted cap during the period
Reconcile aggregated counts to catch keying/aggregation errors
Renegotiate caps that consistently constrain medically necessary volume

Code families most affected

Time- and unit-based services under contracted caps
High-volume ancillary services
Provider-level contracted maximums

Related codes

Denial codes you'll often see alongside CO-222

CO-151 CO-273 CO-45

Payer notes

CO-222 explicitly states the limit is 'not patient specific' — it's a provider/contract aggregate cap, distinct from CO-151 (units not supported by documentation) and CO-273 (a patient benefit/coverage limit).

Not sure how to work CO-222?

Ask D3 whether CO-222 should be appealed, corrected, or simply confirmed — free, backed by CMS, Medicare, and major-payer data.

Ask D3 about CO-222 Ask D3 about CO-222 All denial codes

Medical billing disclaimer

CARC/RARC definitions are the standardized X12 set; group-code semantics follow the X12 Claim Adjustment Group Code standard. Filing and appeal windows vary by payer — the standard anchors shown (Medicare redetermination 120 days from the remittance; Medicare timely filing 12 months from date of service; most commercial payers ~90-180 days) are general references, not a guarantee for any specific plan. Always confirm the rule in the payer's provider manual before acting. D3rx is not responsible for claim outcomes.