Patient Care, Retention, and Experience
When your front desk lists the secondary plan as primary, that claim gets kicked back. One wrong payer order triggers weeks of limbo, scrambled rebilling, and unpaid chair time. Coordination of Benefits (COB) mistakes drain revenue, but they're preventable when you understand the rules and build systems that apply them consistently.
Nov 22, 2025
Understanding COB Basics: Rules That Determine Payer Order
Most COB errors start with confusion about which insurer should be billed first, so mastering the three core determination rules prevents the majority of denials before they happen. The primary carrier processes the claim first. The secondary carrier covers a portion of the remaining balance, up to their own limits. Billing in the wrong order triggers automatic denials.
Three rules govern most decisions.
The birthday rule applies to children covered under both parents' plans: the parent whose birthday falls earlier in the calendar year carries the primary policy.
The active-versus-retired rule states that active employment coverage trumps retiree benefits.
Divorce decrees or court orders override standard rules when legal documents specify which parent must carry primary coverage.
Two denial codes signal coordination problems.
OA 18 flags duplicate billing when you've submitted the same service to both insurers without waiting for the primary's explanation of benefits.
CO 22 signals that the patient has other coverage you didn't list, or you've reversed the payer order.
Both halt payment until you provide corrected information. Once you know which rules apply, the next step is capturing accurate coverage information before treatment begins.
Front-End Prevention: Verification and Documentation
The single most effective way to prevent COB denials is verifying payer order before the patient sits in the chair, because catching coverage changes at check-in costs seconds while fixing denied claims costs hours. Real-time eligibility checks through your practice-management system (using APIs like maxRTE, Vyne, or built-in modules) return active coverage dates, remaining benefits, and primary status within seconds. This catches job changes, divorces, and new policies patients forget to report.
At check-in, ask whether the patient holds more than one dental plan and scan every card. Record subscriber names, birthdates, employer details, and policy numbers. When the patient has dependent coverage, apply the birthday rule and document which parent's plan is primary. Hand the patient a signed coordination-of-benefits form that lists both insurers in the correct order and scan it into their chart.
Repeat this verification at every encounter. Patients switch jobs, get married, lose dependent coverage, or retire without notifying your office. A quick eligibility ping before each appointment catches these changes before you bill the wrong carrier. When your front-end process is tight, the claims you submit reflect accurate payer information from the start.
Claim Submission and Adjudication Protocol
Accurate payer order means nothing if you don't submit claims in the correct sequence, which is why your billing workflow must enforce coordination rules at every step. Submit the claim to the primary insurer first. Wait for the primary's explanation of benefits (EOB) before touching the secondary claim. The EOB shows what the primary paid and what patient responsibility remains. Attach a copy to your secondary claim; most secondary carriers reject claims without it.
Post both payments accurately, matching each to the correct carrier and noting any patient balance.
Track claim status codes daily. The moment you see OA 18 or CO 22, call the insurance company, ask what documentation they need, and resend corrected information the same day. Waiting for an automatic denial cycle adds weeks to your accounts receivable. Manual tracking catches most problems, but technology can identify coordination errors before they ever leave your office.
Technology and Automation for Early Risk Detection
Automated monitoring reveals patterns your team would miss when reviewing claims one at a time, and catching problems early lets you fix workflows instead of endlessly correcting individual mistakes. Pull a denial-code report from your practice management system every week and filter for OA 18 and CO 22. A spike signals a breakdown in your verification workflow: a new employee skipping eligibility checks, or an outdated insurance list. Identifying the pattern lets you retrain staff or update software before dozens more claims get denied.
Rules-based alerts inside your clearinghouse compare each new claim against historical denial data. When the system detects a coordination conflict (billing a secondary carrier first, or submitting without a primary EOB attached), it pushes an instant task to your billing queue. Your team can correct the error before the claim leaves your office.
Dashboards that visualize denial trends help you spot seasonal or systemic issues. If OA 18 codes spike every January, patients are switching plans during open enrollment and your team isn't capturing the changes. If CO 22 denials cluster around one provider or location, you've identified a training gap. Technology surfaces the patterns, but building team capability through consistent training ensures your staff can act on what the data reveals.
Building Team Capability Through Training and Audits
Even the best technology fails when staff don't understand why COB rules matter or how to apply them under pressure, so building deep team knowledge is the only way to sustain low denial rates over time. Schedule a 30-minute training session each quarter covering one coordination topic. One session walks through the birthday rule with real scenarios involving divorced parents. Another explains the active-versus-retired rule and how to verify employment status. A third reviews secondary-carrier requirements. Use actual denied claims from your system as case studies.
Every Friday, review five closed claims that involved multiple insurers. Check that your team listed the correct primary carrier, attached the primary EOB to the secondary claim, and posted payments accurately. When you find an error, note it in a shared folder and schedule a huddle with the employee who filed the claim.
Assign one person as your "coordination champion" to keep training materials current, track audit scores, mentor new hires, and serve as the go-to resource for unusual scenarios. The champion maintains your documentation trail: every eligibility check, call note, and signed COB form lives in the patient chart. Training and audits build capability, but you need metrics to know whether that capability is translating into measurable financial results.
Measuring Results and Refining Your Process
Without clear metrics, you can't tell whether your COB improvements are actually reducing denials and recovering revenue, so tracking three specific numbers turns good intentions into measurable financial gains. Denial percentage divides COB-related denials (OA 18 and CO 22 codes) by total claims submitted. Track this weekly. Average rework days per denied claim counts from denial to payment posting. Claims requiring correction tallies the volume of coordination fixes each month.
Review these numbers monthly with your billing team and front-desk staff. When denial percentage spikes or rework days climb, drill into those claims immediately. Every uptick signals a training gap or workflow breakdown.
Practices that track and act on COB metrics see measurable gains. Fewer resubmissions free up billing staff. Shorter accounts receivable cycles improve cash flow. Write-offs shrink because you're meeting payer timely filing deadlines. These improvements are only sustainable when your practice maintains the staffing levels that allow your team to execute every step properly.
Turn COB Accuracy Into Revenue Recovery
When you verify coverage in real time, follow proper payer order, train your team consistently, and track results, most coordination denials disappear.
Staffing stability makes COB accuracy easier. When your team is short-handed, front-desk employees skip verification steps and billing staff miss follow-up deadlines. Coordination errors multiply because no one has time to do the work right the first time.
Teero helps dental practices maintain consistent hygiene coverage so your administrative team can focus on accuracy. When you're not scrambling to reschedule patients around callouts, your front desk has time to verify insurance properly. Sign up for Teero to see how flexible staffing solutions keep your practice running while your team handles the details that protect revenue.