Two dental plans: how coordination of benefits works

Coordination of benefits is the set of contract rules two insurance plans use to decide which one pays first when a person is covered by both, and how much the second one adds afterwards. Its purpose is to stop the combined payments from exceeding the actual charge, not to make sure the charge is fully paid. The plan that pays first is called primary and the other is secondary.

Most group dental plans in the United States follow ordering rules based on a model regulation published by the National Association of Insurance Commissioners. Florida regulates coordination of benefits for insured group plans, and many employers who self-fund their benefits write near-identical rules into their plan documents. The wording in your own plan is what governs, so everything below describes the common pattern rather than a promise about any particular policy.

People end up with two plans more often than they expect. A married couple who both take dental coverage through work and each add the other as a spouse. A college student on both parents' plans. Someone who starts a new job while still on COBRA from the old one. A retiree with an individual dental policy and a spouse's employer plan. In each case the question is the same: which plan is primary, and what will the secondary really add.

The plan that covers you as the employee or subscriber is primary for you, and the plan that covers you as someone else's spouse or dependant is secondary. That single rule settles most adult cases. If you and your spouse each list the other, your own employer plan pays first on your claims and your spouse's plan pays first on theirs.

When that rule does not settle it, the plans work down a fixed order. The sequence below is the typical one; your plan booklet will have a section titled coordination of benefits or order of benefit determination that states the exact version you are bound by.

1. A plan with no coordination of benefits provision at all is primary over a plan that has one.
2. The plan covering the person as an employee or subscriber is primary over the plan covering them as a dependant.
3. For a child whose parents are married or living together, the birthday rule applies.
4. For a child whose parents are divorced or separated, a court decree naming the parent responsible for health coverage decides; without one, the custodial parent's plan usually pays first, then the custodial parent's spouse, then the non-custodial parent.
5. Active employee coverage is primary over coverage as a retiree or laid-off employee, and over COBRA continuation coverage.
6. If nothing above decides it, the plan that has covered the person longer is primary.

The birthday rule says that when a child is covered by both parents' plans, the plan of the parent whose birthday falls earlier in the calendar year is primary. Only the month and day count, never the year of birth, so a father born on 3 March is primary over a mother born on 20 August regardless of who is older. If both parents share a birthday, the plan that has covered the parent longer pays first.

Wisdom tooth surgery is one of the most common reasons a family first runs into this rule, because the typical patient is between sixteen and twenty-five and still carried on both parents' plans. Plans generally allow dependants to stay on until age 26 under federal rules for medical coverage, but stand-alone dental plans set their own dependant age limits, and some end coverage at 19 unless the child is a full-time student. Check the age limit on both plans before assuming a nineteen-year-old is still covered twice.

The birthday rule applies to children of parents who are married or living together. It does not apply to the parents themselves, and it does not override a court order in a divorce. It is also a common source of claim denials: a secondary plan that thinks it is primary will often pay, discover the other coverage months later, and ask for its money back. Telling both plans about each other at the start avoids that.

An adult child with their own job

A twenty-three-year-old who has dental coverage through their own employer and is also still on a parent's plan is covered as a subscriber under the first and as a dependant under the second. The subscriber rule comes before the birthday rule, so the young adult's own plan is primary and both parents' plans fall behind it.

No. Two dental plans almost never add up to one hundred percent coverage, because each plan's contract caps what it will pay regardless of what the other plan has paid. The secondary plan is calculating its own obligation, not filling the gap to zero. How much it adds depends on which of three coordination methods its contract uses, and the method many employer dental plans use is also the least generous.

The three methods, applied to the same claim, produce very different results. Suppose both plans allow the same fee for a surgical extraction and both pay 80 percent of that allowed fee for oral surgery. The primary pays its 80 percent. What happens next is the whole difference.

Some employer plans use non-duplication or carve-out language rather than standard coordination, which keeps the employer's premium lower, so read the contract rather than assuming. The plan summary may still say the plan coordinates benefits. The phrase to look for is non-duplication of benefits, or a sentence saying the plan will not pay more than it would have paid as primary.

Non-duplication does not always mean zero. If the primary pays 50 percent for surgery and the secondary would pay 80 percent, the secondary may add the 30 percent difference. If the primary's annual maximum has run out partway through the year, the secondary may pay its full benefit on the remaining charge. The only way to know is to have the secondary plan calculate it, which is what a predetermination is for.

Even under standard coordination, each plan applies its own rules to its own share. Having a second plan does not waive any of them, and the secondary is entitled to deny for its own reasons even after the primary has approved.

• Annual maximums. Each plan has its own yearly cap. A secondary with a modest maximum that has already been partly used on cleanings may have little left for surgery.
• Deductibles. Some secondary plans apply their deductible before paying anything, and some credit what the primary counted.
• Waiting periods. A secondary plan that started recently may still be inside a waiting period for oral surgery even though the primary is not.
• Frequency and clinical criteria. Each plan decides separately whether removing an asymptomatic tooth meets its definition of necessary. One can approve while the other declines.
• Anaesthesia rules. Plans differ on whether general anesthesia or deep sedation is a covered benefit for third molar removal, and some pay only when a set number of teeth are impacted.
• Allowed fees. Each plan calculates its payment against its own allowed amount, which for an out-of-network surgeon can be well below the practice's fee.
• Timely filing. Each plan has its own deadline, and the secondary's clock may start when the primary's explanation of benefits is issued.

Sometimes, but less often than patients are told. Medical insurance can be billed first for third molar surgery when there is documented pathology the medical plan recognises, such as a cyst, an infection spreading into the tissues of the face or neck, or a tooth involved in a jaw fracture. In those cases the medical plan may act as primary and the dental plan may then coordinate as secondary. Routine removal of impacted wisdom teeth without that documentation is usually treated as dental by medical plans and denied.

Coordination between a medical plan and a dental plan does not follow the dental ordering rules above. Each contract says whether it covers oral surgery at all, and many medical plans exclude dental services outright, including extraction of impacted teeth and anaesthesia provided in a dental office. Some dental plans say they will not pay for any service a medical plan would have covered, and some medical plans say the reverse. Where both contain that kind of exclusion, a claim can be passed between them with each pointing at the other.

The practical upshot is that a medical claim is worth attempting only when the clinical record supports it. Submitting a routine extraction to a medical plan in the hope that it will pay rarely works and slows the dental claim down. The article on when wisdom teeth bill to medical covers which findings make a medical claim reasonable and which do not.

You file with the primary plan first, wait for its explanation of benefits, then send the secondary plan the same claim form with a copy of that explanation of benefits attached. The secondary cannot calculate its share without seeing exactly what the primary allowed and paid, so a claim sent to both at once is usually held or returned. Expect the second claim to take another few weeks after the first is processed.

The Wisdom Tooth Clinic is out of network with every carrier. That changes who does the filing but not the rules. Patients pay the practice at the time of treatment, and the practice provides an itemised statement with the procedure codes, tooth numbers and dates each plan needs. Many plans pay out-of-network benefits to the subscriber rather than to the practice, and with two plans that means two separate reimbursement cheques, on two schedules, possibly to two different family members.

1. Confirm which plan is primary using the order above, and tell each plan that the other exists. Most plans send an other-coverage questionnaire; answer it before the surgery, not after a denial.
2. Request a predetermination from the primary plan, and if the secondary will review one, from the secondary as well, naming the coordination method it will apply.
3. After treatment, submit the claim to the primary with the itemised statement and any radiograph or narrative the plan asks for.
4. When the primary's explanation of benefits arrives, send the claim and that explanation of benefits to the secondary.
5. Keep copies of both explanations of benefits. If the primary later reprocesses the claim, the secondary will need the corrected one.

The subscriber on each plan is the person the plan corresponds with. For a dependant, that means the explanation of benefits goes to whichever parent holds the plan, and a young adult patient may not see either one unless they ask.

Ask the secondary plan which coordination method it uses, how much of its annual maximum remains, whether any waiting period applies to oral surgery, and whether it covers general anesthesia or deep sedation for third molar removal. Those four answers tell you whether the second plan is likely to add anything at all. Ask for the answers in writing or note the date, time and reference number of the call.

Ask the primary plan the same questions about maximum, waiting periods and anaesthesia, plus whether it pays out-of-network benefits to the subscriber or the provider, and what allowed amount it uses for out-of-network oral surgery. A plan that calculates against a low allowed amount will pay a percentage of that figure, not of the fee charged.

• Does this plan consider itself primary or secondary for this patient, and on what rule?
• Is coordination standard, non-duplication or carve-out?
• How much annual maximum remains for this calendar or plan year, and when does it reset?
• Is there a waiting period for oral surgery, and has it been met?
• Is general anesthesia or deep sedation covered for removal of impacted third molars, and under what conditions?
• Will the plan accept a predetermination, and how long is an approval valid?
• What is the timely filing limit for the secondary claim, and when does it start?

A predetermination is an estimate, not a commitment. Plans state that payment depends on eligibility and remaining benefits on the date of service, and on the claim that is actually submitted. The article on predetermination before oral surgery explains what an approval does and does not bind the plan to.

There are situations where the realistic value of a second plan for wisdom tooth surgery is close to nothing, and planning as though it will pay leads to an unwelcome surprise. The clearest is a secondary with non-duplication language and the same surgery percentage as the primary. Another is a secondary dental plan that was added mainly to pick up coverage for surgery already scheduled, because waiting periods for oral surgery are commonly six to twelve months.

Some families consider keeping or buying a second policy specifically to cover an upcoming extraction. Whether that makes sense is a financial decision that depends on the premium, the waiting period, the maximum and the coordination clause, and it is not something this practice can advise on; we are not insurance or financial advisers. The facts worth putting side by side are the premium for the months you would hold the plan, the waiting period, the annual maximum, and the coordination method stated in the contract.

Timing across plan years can matter more than a second plan. Because each plan resets its annual maximum on its own date, a patient whose treatment is planned in stages may find that spacing appointments across a reset uses more of both plans' benefits than doing everything at once. That has to be weighed against the clinical reasons for removing teeth together, including one recovery, one anaesthetic and one day off rather than two.

Coordination of benefits exists to stop plans overpaying, and most of its rules work in that direction. Treat a second plan as a possible partial offset, find out its coordination method before treatment, and plan the cost of surgery around what the primary plan is likely to pay. If the secondary adds something, that is a reimbursement to welcome rather than one to count on. The article on claiming reimbursement after oral surgery walks through the paperwork once treatment is done.