On July 1, 2025, the Centers for Medicare & Medicaid Services (CMS) began using the KX modifier for certain dental claims. This change has helped to ensure that dental services linked to covered medical procedures are appropriately documented and reimbursed.
Important Note: This guidance does not pertain to Medicare Advantage supplemental dental benefits. Dentists are not required to be enrolled in Medicare or to formally opt out of Medicare to submit claims for dental services covered under these supplemental benefits.
What is the KX Modifier?
The KX modifier is used to indicate that a dental service is inextricably linked to a Medicare-covered medical procedure. It indicates that the dental service is medically necessary for the success of a covered medical treatment and that care coordination with a physician has been established.
Routine dental services are generally excluded from Medicare coverage. However, CMS now allows payment for dental services that are linked to covered medical services, such as organ transplants or cancer treatment.
When Should You Use the KX Modifier?
Dentists must coordinate care with a physician and document this using the ADA Medicare Referral Form, which should be retained in the patient’s record.1
Use the KX modifier for dental services that are clinically necessary to ensure the success of a Medicare-covered medical procedure. Examples include dental care prior to:
- Organ transplants
- Cardiac valve replacements
- Chemotherapy or radiation for cancer
- Dialysis for end-stage renal disease
- Head and neck cancer treatment
How to Submit Claims
Dentists must append the KX modifier to the procedure code on the ADA Dental Claim Form or the 837D electronic claim form.
Enter “KX#” followed by the procedure description in Item 30 of the “Record of Services Provided” section- example: KX# limited oral eval. Include the modifier for the associated procedure only if necessary.
CMS now accepts electronic dental claims using the 837D format, which supports the use of administrative modifiers such as KX.2 For electronic submissions (837D v5010), consult your practice management software vendor for guidance on reporting modifiers.
Claims submitted to Cigna Dental on behalf of HealthSpring Medicare Advantage with the KX Modifier will be routed to HealthSpring Medicare Advantage for processing.
Medicare Enrollment Requirements
To submit claims for covered services, dentists must be enrolled in Medicare (as participating or non-participating) or have opted out and entered into a private contract with the beneficiary. If a dentist provides a covered service and charges the patient, they are legally required to submit a claim to Medicare.
CMS delayed the mandatory use of the KX (and GY) modifiers until July 1, 2025, to allow time for provider education and system updates.3
Questions
For more information on KX dental claim modifier requirements and recent updates, please review the ADA.org1 and CMS.gov4 resources linked below. If you have any additional questions about these requirements, you can contact HealthSpring Dental Customer Service at 866-213-7295.
If you have questions about the HealthSpring Medicare Advantage supplemental dental benefit, managed by Cigna Dental, feel free to contact our Cigna Provider Service team at 800.Cigna24 (800.244.6224).
1. Medicare claims for dental services to require administrative modifier codes
2. Dentists can now submit Medicare claims electronically
3. CMS 2025 Medicare physician-fee-for service final rule released
4. Medicare Dental Coverage | CMS