Coding for non-open procedures involving arthrodesis of the SI joint has continued to evolve since 2014, when the AMA CPT Editorial Panel issued a permanent Category I CPT code to report minimally invasive or percutaneous SI joint fusion procedures: CPT 27279, Arthrodesis, sacroiliac joint, percutaneous or minimally invasive (indirect visualization), with image guidance, includes obtaining bone graft when performed, and placement of transfixing device. This code became effective in January 2015.

In May 2022, a new Category III CPT code (0775T) was introduced to describe percutaneous placement of an intra-articular stabilization device or implant into the sacroiliac joint using a minimally invasive technique that did not transfix the SI joint. It remained as a Category III code until January 2024, when code 0775T was deleted and replaced with a new Category I code, 27278. This was previously covered in a SpineLine article from March-April 2024.

Significant confusion arose as to proper use of these two codes. Therefore, multiple discussions occurred to hone and revise the code descriptors to improve the clarity. As of January 2026, there is updated language to differentiate 27278 and 27279 usages.

The updated language for the CPT codes is no longer relying on the “transfixing device” language. Instead, now, the differentiating factor involves whether the device being placed pierces the lateral or medial cortices of the ileum and lateral cortex of the sacrum, or whether the device is placed without this cortical piercing. The updated descriptors are as follows:

Both of these codes are meant for indirect visualization of the joint, relying on imaging modalities to visualize the joint (percutaneous). It is important to note that the language for code 27279 allows the use of the code for intra-articular, trans-articular or hybrid (i.e., incorporating both intra-articular and trans-articular mechanisms) devices.1

For both codes 27278 and 27279, when procedures are performed bilaterally, the appropriate code should be appended with modifier –50.

A formal open approach, whether it be posterior, anterior or trans-ileal, with direct visualization of the joint, decortication of the joint and grafting with stabilization would fall into the 27280 code.

It is important to note that whether done open or with indirect visualization, SI Joint Arthrodesis have significant appropriate-use criteria to determine medical necessity. In 2021, NASS released coverage policy recommendations concerning Minimally Invasive Sacroiliac Fusion available online.