CO-143 means you got paid, but not all of it yet. The payer kept back part of the allowed amount to release later. In managed care, the most common reason is a withhold, a share of each payment that the plan holds until the end of a contract period and then returns based on cost or quality results. Because the money may come back, a CO-143 amount shouldn’t be posted as a plain write-off. You need to track it as money still owed under the contract. (Primary source: X12 Claim Adjustment Reason Codes)
In brief: CARC 143 reads “Portion of payment deferred.” Find the contract term that allows the deferral, post the amount to a tracking account rather than a write-off, and match it to the settlement when the plan pays it out or keeps it.
Part of our denial codes library. Written by Manikandan J, CPC, CRCR, who has reconciled managed care contracts and year-end settlements for physician groups. Published 21 October 2026. Last updated: 21 October 2026. Code wording quoted word for word from X12.
Reason code 143 in the X12 list
| Field | X12 text |
|---|---|
| Code | 143 |
| Description | “Portion of payment deferred.” |
| Start | 02/28/2001 |
Source: X12 Claim Adjustment Reason Codes, checked 21 October 2026.
Deferred vs denied vs reduced
| Code | What happened | Will the money come back? |
|---|---|---|
| CO-143 | Part of the payment is held for later | Maybe, under the contract terms |
| CO-45 | Charge is above the contract rate | No, it’s a write-off |
| CO-253 | Federal sequestration cut | No, set by law |
A settlement is the later payment or final accounting where the plan releases, keeps or splits the deferred money. A risk pool is the shared fund a plan uses to decide how much of the withhold to give back. Federal rules for Medicare Advantage physician incentive plans, including withholds, are in 42 CFR 422.208.
Example scenario (fictional names), part 1
CO-143 Denial Example: What Happened
Monique Laurent is the billing lead at Eastgate Pediatrics. The practice signed a new contract with Silver Ridge Health Partners, a fictional managed care plan. Soon every paid well-child visit, such as 99392 with Z00.129, came in a little short.
Each line showed CAS*CO*143 for the same share of the allowed amount, with remark LQ*HE*N381, “Alert: Consult our contractual agreement for restrictions/billing/payment information related to these charges.” The practice’s system had posted it all to contractual write-off.
Was the money lost, or just parked? Keep reading, or jump to how the CO-143 denial was resolved.
Remark codes you may see with CARC 143
| RARC | X12 wording |
|---|---|
| N381 | “Alert: Consult our contractual agreement for restrictions/billing/payment information related to these charges.” |
| N552 | “Payment adjusted to reverse a previous withhold/bonus amount.” |
N552 often shows up later, when the plan pays out or reverses the held amount. See the X12 RARC list.
How to handle a CO-143 adjustment
- Find the contract clause. Look for words such as withhold, deferral or risk pool, and the percent or method.
- Check the math. Compare the CO-143 amount on a few lines to the contract’s withhold share of the allowed amount.
- Post to a tracking account. Use a separate adjustment code so the money doesn’t vanish into write-offs.
- Keep a running total. Track deferred amounts by plan and contract year.
- Match the settlement. When the plan pays out, often with N552 or a separate report, apply it against the tracked total.
- Ask for the settlement report. If nothing arrives after the contract period, ask the plan’s provider relations team.
Example scenario (fictional names), part 2
How the CO-143 Denial Was Resolved
Monique read the contract. It had a withhold clause tied to a shared risk pool, settled once a year. The CO-143 amounts matched the withhold share on every line she checked.
Fix: no appeal. She moved the CO-143 amounts from contractual write-off to a withhold receivable account. Then she set up a monthly report of the running total.
Outcome: at year end the plan sent a settlement statement and released part of the pool. Monique matched it to her report to the dollar. The rest was kept under the contract’s risk terms.
Names and details are illustrative; no real patient data.
Worked example (illustrative)
Consider a workers’ compensation claim for a long course of physical therapy. The payer pays part of each bill now and defers the rest until a utilization review finishes. The clinic sees CO-143 on each line, tracks the deferred share, and follows up when the review closes. Writing it off would have hidden money the payer still owed.
Common mistakes with deferred payments
- Posting CO-143 as a write-off. The settlement then has nothing to match against.
- Billing the patient. It’s a CO amount, and the patient doesn’t owe it.
- Forgetting the settlement date. Some contracts give a short window to dispute the final numbers.
- Not checking the rate. A wrong withhold share can mean the plan loaded the wrong contract.
Related codes
- CO-45: charge exceeds the contracted fee arrangement.
- CO-24: charges covered under a capitation agreement or managed care plan.
- CO-253: sequestration reduction.
- CO-144: incentive adjustment.
Recap
CO-143 means part of the payment is on hold for later, often under a contract withhold. Find the clause, check the math, post it to a tracking account and match it to the settlement. Don’t write it off, and don’t bill the patient for it.
FAQ
What does denial code CO-143 mean?
Part of the payment was held back for later. It reads “Portion of payment deferred.”
Is CARC 143 a write-off?
Not right away. The money may come back under the contract, so track it until the settlement.
Can I bill the patient for CO-143?
No. It’s a CO adjustment between you and the payer.
What is a withhold?
It’s a share of each payment a plan keeps until the end of a contract period, then pays back based on results.
What does N552 mean?
It shows the payer reversed a previous withhold or bonus amount, often at settlement.
When does deferred money get paid?
It depends on the contract. Many withholds settle once a year after the contract period ends.
Sources
How we checked: each code quote on this page was matched word for word with the X12 CARC and RARC lists on 21 October 2026.
- X12, Claim Adjustment Reason Codes (CARC 143, 24, 45, 144, 253). Accessed 21 Oct 2026.
- X12, Remittance Advice Remark Codes (N381, N552). Accessed 21 Oct 2026.
- eCFR, 42 CFR 422.208, physician incentive plans. Accessed 21 Oct 2026.
Last updated: 21 October 2026 ยท Educational content; not legal advice.