Tips For Coding And Reimbursement Of ¾ Crowns, Inlays, And Onlays
Estela Vargas, CRDH, CEO Remote Sourcing
Before considering coding for reimbursement by insurance plans for inlays, onlays, and ¾ crowns, you must know how they are defined in the Current Dental Terminology by the American Dental Association(ADA). Coding what you do is the rule, but you must know if what you think you are coding is precisely what was performed on the patient, particularly when it comes to inlays, onlays, and 3/4 crowns.
Many insurance coordinators will see a code for a procedure on a treatment plan, but little documentation supports the clinical notes' choice. If it isn’t in the notes, it didn’t happen. Consult the Current Dental Terminology manual from the ADA for the codes and their descriptors and nomenclature. Meet with the clinical team to ensure proper notes are in the patients’ chart.
Inlays, onlays, and 3/4 crowns are defined as “indirect” restorations because they are fabricated outside of the mouth through the use of impressions that are physical or digital. The remaining healthy tooth structure is a determining factor in restoration choice. If all cusps are intact, many dentists choose an inlay if it is more appropriate than a filling. An onlay will cover one or more missing cusps (this must be in the narrative). ¾ crowns cover all of the cusps on posterior teeth, extend beyond the height of contour on the covered surfaces and restore three of the four proximal surfaces.
Many PPO plans have an “alternate benefit clause” for direct restorations if the proof has not been presented for indirect restorations. Some PPO plans have a LEAT clause that dictates only the cheapest alternative treatment will be paid. The cheapest material is often amalgam. Other plans exclude inlays as not a covered benefit even if warranted by clinical notes.
Many plans require that two or more cusps of a tooth be involved in the onlay and may specify how much of the cusp incline must be involved (usually 80 percent or more) to qualify for benefits.
Benefits of a dental inlay are to conserve much more of the tooth structure, not as much drilling is required to prep the tooth, and inlays can help increase the tooth strength by 50 percent, repair small fissures and secure the structural integrity of a tooth.
The value is there for the inlay, and usually, no one wants amalgam because it is unsightly and contains silver, tin, and copper metals and 50% mercury*. However, when the patient learns that their plan benefits will not cover an inlay, they often choose the least expensive alternative, amalgam.
Often the plan policy dictates that 50% more of the tooth structure must be missing before an indirect restoration is adjudicated for payment. The patient who only wants what the insurance will pay often gets an extensive filling or some interim restoration with a guarded long-term prognosis due to the chewing forces of the posterior molars.
Of course, it isn’t fair that the insurance plan won’t pay when you have provided what you feel is the best restoration for the patient. When the contract says, “not a covered benefit,” it doesn't matter.
What can you do to increase your odds of getting paid? Follow these tips:
1. Complete insurance verification of each patient before the patient arrives for an appointment. Acquire benefits by website, email, fax, or phone. A phone call is often necessary to get the finer details of the benefits, such as the history of x-rays, crowns, bridges, implants, periodontal services, age limitations, and frequency limitations.
2. Send in predetermination (pre estimate) of dental benefits, especially if it is a requirement of the plan administrator or the patient requests it. Some plans require it for services totaling more than 300.00.
3. Most insurance plans have frequency limitations on all restorations. Some have a ten-year or longer limitation for onlays, inlays, and crowns. The insurance company will ask for information on the previous restoration, type, and placement age.
4. Core build-ups are never paid when billed with an inlay or an onlay because, by descriptor, there is sufficient tooth structure to support the restoration.
5. Submitting a clear written narrative explaining the number of cusps and surfaces replaced and the long-term prognosis is helpful. If the existing restoration has been damaged by trauma, there may be benefits not subject to the frequency limitation.
6. Replacement restorations: provide the previous seat date and reason for replacement from clinical notes.
7. If reporting a buildup or resin composite on the same tooth at the same visit, the insurance plan will deny it.
8. Providing diagnostic quality x-rays-pre and post, narrative, recent periodontal charting, and photographs will alleviate the need to submit additional information.
9. The predetermination request should contain a narrative explaining why an inlay or onlay is the best treatment and an attachment of pertinent documentation. For example:
(a) "Vertical fracture lines are apparent on #19. The patient reports pain to cold" (Attach an intraoral photo.) for fracture lines; an intra-oral image with an x-ray will show the integrity of the enamel surface, the tissue, bone, and pulp. (it is important to note that the fracture does not extend past the CEJ, if it does, it will be denied for poor prognosis.)
(b) "Tooth #18 has undermined cusps on MF, ML, and DL. Eighty percent of the cusp incline for these cusps is involved." (Attach an intraoral photo.) Sometimes, the cusp decay isn’t evident until the doctor starts the prep. In these situations, it is good to note “ML cusp obliterated during caries removal” and provide an intraoral photo of the prep showing the decay or cusps missing.
10. It is not correct to report an inlay code and an onlay code on the same tooth. The onlay code is inclusive of the inlay.
Summary: To receive reimbursement for the services you provide to patients with insurance plans, the entire team, clinical, and administration should know the difference between an inlay an onlay and a ¾ crown.
Patients will gain trust when given knowledgeable answers to questions regarding these similar restorations. Excellent, detailed clinical notes help create narratives for insurance plans and create a solid, credible dental history.
