Posterior arthrodesis of the atlas and axis (C1-C2), surgically fusing the first and second cervical vertebrae through a posterior approach to stabilize the upper cervical spine.
Verified May 8, 2026 · 5 sources ↓
- Medicare
- $1,499.03
- Total RVUs
- 44.88
- Global, days
- 90
- Region
- Spine
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 5 cited references ↓
- Preoperative imaging (CT or MRI) confirming C1-C2 instability or pathology at the level treated
- Specific diagnosis driving instability — fracture, rheumatoid arthritis, congenital anomaly, tumor, or infection — documented with ICD-10 code alignment
- Operative note naming the posterior approach, graft type and source (autograft, allograft, or synthetic), and instrumentation used
- Documentation of failed or contraindicated conservative management, or clear acute/emergent indication that waives that requirement
- Neurological status documented pre- and intraoperatively, including baseline deficits if present
- Medical necessity narrative explaining why C1-C2 fusion is required versus observation or alternative treatment
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 5 cited references ↓
CPT 22595 covers posterior arthrodesis of the C1-C2 motion segment — the atlantoaxial joint. The surgeon accesses the upper cervical spine through a posterior midline incision, prepares the joint surfaces, places bone graft material, and typically secures the construct with instrumentation (screws and rods). The goal is rigid stabilization of a segment that, when unstable, poses direct risk to the spinal cord and brainstem.
Indications include atlantoaxial instability from odontoid fractures, os odontoideum, rheumatoid arthritis (which erodes the transverse ligament), congenital abnormalities, and destructive tumors or infections at C1-C2. Because the atlas and axis contribute roughly 50% of cervical rotation, fusion at this level has significant functional consequences — patients lose most head rotation, which drives the medical necessity documentation requirement.
The code carries a 90-day global period. All routine post-op visits, collar adjustments, and imaging review within that window are bundled. If a new problem or complication requires a separately identifiable E/M visit during the global, modifier 24 is required. When additional spinal levels are fused in the same session, report the appropriate arthrodesis add-on codes alongside 22595. Instrumentation codes (e.g., 22840–22842 series) and bone graft codes are reported separately and are not bundled into 22595.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
| Work RVU | 20.12 |
| Practice expense RVU | 17.09 |
| Malpractice RVU | 7.67 |
| Total RVU | 44.88 |
| Medicare national rate | $1,499.03 |
| 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 | $1,499.03 |
HOPD (APC 5115) Hospital outpatient department | $13,116.76 |
ASC (PI G2) Ambulatory surgical center (freestanding) | $6,804.43 |
Common denial reasons
The recurring reasons claims for CPT 22595 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Lack of documented imaging findings at C1-C2 correlating with the operative level — payers flag level mismatches between radiology reports and operative notes
- Absent or insufficient conservative treatment trial documentation without a documented emergent or acute exception
- Bundling errors: billing 22595 with instrumentation or graft codes that require separate reporting but were either missed or incorrectly bundled
- Medical necessity denial when the clinical indication (e.g., mild degenerative change without instability) does not meet payer criteria — Aetna CPB 0743 and similar policies require instability or cord-risk evidence
- Global period violations: billing routine post-op E/M visits within the 90-day global without modifier 24
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01Can 22595 be billed with instrumentation codes in the same session?
02What modifier applies if the surgeon performs both C1-C2 fusion and an adjacent level fusion in the same session?
03Does 22595 require prior authorization from most commercial payers?
04What is the global period for 22595 and what does it include?
05How does site of service affect reimbursement for 22595?
06What ICD-10 codes most commonly support medical necessity for 22595?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CMS Physician Fee Schedule 2026
- 02cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=59674&ver=15
- 03aetna.comhttps://www.aetna.com/cpb/medical/data/700_799/0743.html
- 04medtronic.comhttps://www.medtronic.com/content/dam/medtronic-wide/public/united-states/customer-support-services/reimbursement/spinal-procedures-billing-and-coding-guide.pdf
- 05static.aapc.comhttp://static.aapc.com/e7fe2e86-ee05-475b-ac2c-bdc28fea95c1/08ebe3b9-e3f6-479e-a867-b13ffda2064c/1aa7e197-97f3-4c76-85a2-4ca4c59209f1.pdf
Mira AI Scribe
Mira's AI scribe captures the posterior approach, C1-C2 level confirmation, graft type and source, instrumentation details, and intraoperative neurological status from surgeon dictation in real time. This prevents the most common audit flag on 22595 — operative notes that specify 'posterior cervical fusion' without naming the specific levels, approach, and graft used — which triggers medical necessity review and documentation insufficiency denials.
See how Mira captures CPT 22595 documentation