Fusion · Spine

Anterior interbody arthrodesis of the lumbar spine using an anterior or anterolateral approach, including the minimal discectomy required to prepare the interspace for fusion.

Verified May 8, 2026 · 6 sources ↓

Medicare: $1,423.88
Total RVUs: 42.63
Global, days: 90
Region: Spine

Drawn from AAPCMdclarityHealthcareinspiredllcMedtronicCMS

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Operative note must specify the surgical approach by name (ALIF, DLIF, OLIF, or anterior/anterolateral retroperitoneal) — vague approach language triggers audit flags.
Clearly document that discectomy was performed only to prepare the interspace for fusion, not for neural decompression, to avoid downcoding or upcoding disputes.
Identify each lumbar interspace treated (e.g., L4–L5, L5–S1) to support 22558 for the primary level and 22585 for each additional level.
Document implant type and manufacturer if an interbody device was placed, to support separate cage coding under 22853/22854.
When modifier 62 is used, each co-surgeon's operative note must individually describe their distinct surgical contribution to the procedure.
Medical necessity documentation must link the diagnosis (e.g., degenerative disc disease, spondylolisthesis, disc herniation with instability) to the decision for arthrodesis over non-surgical management.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 59 Distinct service 62 Co-surgeons 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

22558 covers anterior lumbar interbody fusion (ALIF) at a single lumbar interspace, approached through the abdomen or retroperitoneally. The code bundles the minimal discectomy performed solely to prepare the disc space — not a separate decompressive discectomy. It is also the correct code for direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF) at the lumbar level.

For each additional lumbar interspace fused through the same anterior approach in the same session, add 22585 — no modifier 51 on the add-on. Interbody implants (cages) are reported separately under 22853 or 22854 depending on device type. If morselized allograft or osteopromotive material is placed, report 20930 as an add-on. Anterior instrumentation, if used, is reported separately; do not assume it bundles into 22558.

The 90-day global period covers all routine post-op care through day 90. Anything unrelated to the fusion billed inside that window needs modifier 24 or 25. When an orthopedic and neurosurgical co-surgeon each perform distinct portions of the anterior approach and fusion, both append modifier 62 — modifier 62 may also carry over to the add-on 22585 if both surgeons remain primary for the full procedure.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	22.94
Practice expense RVU	13.2
Malpractice RVU	6.49
Total RVU	42.63
Medicare national rate	$1,423.88
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	$1,423.88
HOPD (APC 5117) Hospital outpatient department	$27,721.73
ASC (PI J8) Ambulatory surgical center (freestanding)	$20,101.23

Common denial reasons

The recurring reasons claims for CPT 22558 get rejected.

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

Bundling of the minimal discectomy component into a separately billed decompressive discectomy code — the discectomy in 22558 is included; only a distinct decompressive discectomy at a different level may be separately billable.
Failure to append modifier 62 when two surgeons each billed 22558 independently as primary surgeon without the modifier, resulting in one claim being denied as a duplicate.
Incorrect add-on code reporting — billing 22585 with modifier 51 instead of as a standalone add-on, causing the add-on to be reduced or denied.
Missing or insufficient medical necessity documentation tying the diagnosis to anterior fusion specifically, particularly when a posterior approach would have been simpler.
Cage or interbody device code (22853/22854) denied for lack of implant documentation when billed alongside 22558 without operative implant records.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01Is 22558 the right code for DLIF and OLIF?

Yes. Per Medtronic's 2026 Billing and Coding Guide, 22558 is the correct code for direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF) at the lumbar level, since both use an anterior interbody technique.

02How do I code a second lumbar level fused through the same anterior approach?

Add 22585 for each additional interspace. Do not append modifier 51 to 22585 — it's an add-on code and modifier 51 is not appropriate. 22585 can also carry modifier 62 if two co-surgeons remain primary for the full multilevel procedure.

03Does 22558 include the interbody cage?

No. The cage is reported separately under 22853 (single device) or 22854 (multiple devices). If you place two cages at two levels, report 22558 + 22585 + 22853 x2, assuming single-device-per-level billing is supported by your operative note.

04When do I use modifier 62 versus modifier 80 for a co-surgeon on 22558?

Use modifier 62 when two surgeons each perform a distinct primary portion of the procedure — common in ALIF where a vascular or general surgeon manages the approach exposure and the spine surgeon performs the fusion. Use modifier 80 when one surgeon is assisting the primary surgeon throughout, not performing a distinct portion.

05Can I separately bill a decompressive discectomy with 22558?

Only if a distinct, separate decompressive discectomy is performed at a different level than the fusion interspace, and the operative note clearly documents it as a separate decompressive act. The minimal discectomy at the fused level is bundled into 22558 and cannot be billed separately.

06What modifier applies if I need to perform a related unplanned return to the OR during the 90-day global for this fusion?

Use modifier 78 for an unplanned return to the OR for a procedure related to the original fusion during the 90-day global period. Use modifier 79 if the return-to-OR procedure is unrelated to the fusion.

07Is modifier 22 supportable for a complex ALIF with extensive adhesions or revision anatomy?

Yes, but documentation must be explicit. The operative note must describe the specific complicating factors — prior abdominal surgery, vascular adhesions, aberrant anatomy — and the surgeon should include a separate letter quantifying the additional time and work. Modifier 22 without supporting narrative is routinely denied.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures the approach name (ALIF, DLIF, OLIF), the specific interspace(s) treated, whether discectomy was performed solely for interspace preparation versus decompression, implant type and quantity, use of allograft or osteopromotive material, and each surgeon's distinct role when two surgeons are present. That specificity prevents the most common 22558 denials: bundled discectomy disputes, missing cage documentation, and co-surgeon claims rejected for absent modifier 62 support.

See how Mira captures CPT 22558 documentation