Surgical · Other

Open treatment of a temporomandibular joint (TMJ) dislocation using operative techniques

Verified May 8, 2026 · 5 sources ↓

Medicare: $713.44
Work RVU: 12.63
Global, days: 90
Region: Other

Drawn from CMSAAOSAaoms

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 5 cited references ↓

Document that closed reduction was attempted or contraindicated, and explain why open operative treatment was required
Specify the operative approach and anatomical structures accessed during the procedure
Record duration and chronicity of the dislocation, including any prior episodes or treatment history
Include laterality explicitly — left, right, or bilateral — in both the operative note and the claim
Note any concurrent TMJ pathology (e.g., ankylosis, condylar fracture) to justify the open approach and support medical necessity
Capture the patient's functional limitations pre-operatively (limited mouth opening, pain, malocclusion) to support necessity

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 57 Decision for surgery 58 Staged or related 62 Co-surgeons 74 Discontinued post-anesthesia 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 21490 covers operative (open) treatment of a temporomandibular joint dislocation — a relatively uncommon procedure reserved for cases where closed manipulation has failed or is not appropriate. It sits in the musculoskeletal section of CPT and carries a 90-day global period, meaning all routine pre- and post-operative care is bundled through day 90.

This is a low-volume code with no dominant billing specialty identified in CMS utilization data. It is most commonly performed by oral and maxillofacial surgeons or select craniofacial/orthopedic specialists. Because the TMJ is anatomically complex and dislocation may occur in the context of broader jaw pathology, documentation must clearly distinguish the dislocation treatment from any concurrent procedures on the same joint or adjacent structures.

Site of service matters here: HOPD and ASC payments differ substantially (see the Site of Service comparison table). If a same-day E/M is billed for the decision to proceed with open treatment, modifier 57 applies — this is a 90-day global procedure, so the day-before or day-of decision visit requires 57 to be separately payable.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (12.63) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (21.36) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	12.63
Practice expense RVU	7.29
Malpractice RVU	1.44
Total RVU	21.36
Medicare national rate	$713.44
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$713.44
HOPD (APC 5164) Hospital outpatient department	$3,387.27
ASC (PI J8) Ambulatory surgical center (freestanding)	$1,881.17

Common denial reasons

The recurring reasons claims for CPT 21490 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Medical necessity not established — payer requires documented failure of closed reduction before approving open treatment
Missing or ambiguous laterality on the claim causes processing rejection or incorrect payment
Concurrent TMJ procedures billed same-day without appropriate modifier or distinct documentation, triggering NCCI bundling edits
Pre-authorization not obtained — many payers require prior auth for open TMJ surgery
E/M service billed same-day without modifier 57, denied as bundled into the 90-day global

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01What distinguishes 21490 (open) from closed treatment of TMJ dislocation?

Closed reduction of TMJ dislocation is reported with a different code and does not require surgical access. 21490 applies when operative (open) intervention is performed — typically because closed manipulation failed, the dislocation is chronic or recurrent, or the anatomy requires direct surgical access to reduce the joint.

02Does 21490 carry a global period, and what does that include?

Yes — 21490 has a 90-day global period. That covers the surgery, the day-before visit, and all routine post-operative care through day 90. Any unrelated E/M visit billed in that window needs modifier 24. A new unrelated surgical procedure needs modifier 79.

03Can I bill modifier 50 for bilateral TMJ dislocation treated at the same operative session?

Yes, modifier 50 applies if both TMJs are treated operatively in the same session. Some payers want LT and RT on separate line items instead. Confirm your payer's preference before submitting, as Medicare and many commercial payers differ on bilateral reporting conventions.

04When does modifier 57 apply to a same-day E/M with 21490?

Append modifier 57 to the E/M code when the decision to perform open TMJ dislocation treatment is made on the day of or the day before surgery. Because 21490 carries a 90-day global, modifier 57 is required — not modifier 25 — to allow separate payment for that visit.

05What if the patient returns to the OR during the global period for a related complication?

Use modifier 78 for an unplanned return to the OR for a complication related to the original TMJ procedure within the 90-day global. Modifier 79 applies only if the return procedure is entirely unrelated to the original dislocation treatment. Do not invert these — modifier 78 is for related returns, 79 for unrelated.

06Is prior authorization typically required for 21490?

Most commercial payers and many Medicaid managed care plans require prior authorization for open TMJ surgery. Obtain auth before scheduling and document the medical necessity basis — especially prior failed conservative or closed treatment — in the auth request.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira Scribe

Mira's AI scribe captures the operative approach, laterality, documented failure or contraindication of closed reduction, pre-operative functional deficits, and any concurrent TMJ pathology from dictation. This prevents the most common denial trigger — missing medical necessity justification for open versus closed treatment — and ensures laterality is explicit on the claim before it leaves the practice.

See how Mira captures CPT 21490 documentation