Sp bone agrft morsel add-on

CPT code 20937 represents the additional work of preparing and placing morselized (ground-up) bone graft material taken from the patient's spine during spinal surgery. This is an add-on code, meaning it's only billed alongside a primary spinal procedure.

Showing rates for

National Average

Base Medicare rate

$162.38

This calculator gives a typical-case estimate using standard Medicare modifier rules. Actual payment depends on payer policies, documentation, code-specific CMS status indicators, and locality. Verify before billing.

RVU breakdown

Work RVU

2.79

PE RVU (NF)

1.43

MP RVU

0.8

Total RVU

5.02

Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High

NCCI bundling edits

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Billing tips

Always verify the primary procedure code allows 20937 as an add-on. This code cannot be billed alone and is only appropriate with specific spinal arthrodesis codes (22548-22812, 22840-22855).
Impact: Prevents 100% denial; ensures $162.38 reimbursement is not automatically rejected for lack of primary procedure
Document the exact source of the morselized bone graft (spinous process, lamina, facet) and the morselization technique used. Many audits focus on whether the graft material was truly autogenous versus allograft or bone substitute.
Impact: Reduces audit risk by 60-70%; prevents recoupment of $162.38 payment during post-payment review
Report 20937 only once per operative session regardless of the number of levels grafted, unless documentation clearly supports separate and distinct harvesting procedures at different anatomic sites.
Impact: Prevents overbilling denials; most payers limit to one unit per session, attempting multiple units risks denial of all but one unit ($162.38 loss per extra unit)
Do not report 20937 when bone removed during decompression (laminectomy) is simply saved and reused. The code requires additional work beyond what is included in the primary decompression procedure.
Impact: Critical compliance issue; billing for incidental bone harvest can trigger fraud investigation; protects against recoupment and potential penalties
For commercial payers, verify coverage policies as some require pre-authorization or have specific medical necessity criteria beyond Medicare. Document why autograft was chosen over alternatives.
Impact: Improves first-pass payment rate by 30-40%; reduces appeals workload and accelerates $162.38 reimbursement timeline

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Frequently asked questions

What is the Medicare reimbursement rate for CPT code 20937 in 2025?

The 2025 Medicare national average reimbursement for CPT 20937 is $162.38 for both facility and non-facility settings. This rate is based on 5.02 total RVUs (2.79 work RVU, 1.43 PE RVU, 0.8 MP RVU) multiplied by the 2025 conversion factor of 32.3465.

Can CPT 20937 be billed alone or does it require a primary procedure?

CPT 20937 is an add-on code and cannot be billed alone. It must be reported with a primary spinal arthrodesis procedure code such as 22548-22812 or 22840-22855. Billing 20937 without an appropriate primary procedure will result in automatic denial.

How many times can I bill CPT 20937 during a single operative session?

Generally, CPT 20937 should be reported only once per operative session, regardless of the number of spinal levels being fused. Multiple units are appropriate only when documentation clearly supports separate and distinct harvesting procedures at different anatomic sites, which is uncommon. Most payers will deny multiple units without exceptional documentation.

What is the difference between CPT 20937 and 20938?

CPT 20937 is for morselized (ground into small pieces) autogenous bone graft harvested from the spine, while CPT 20938 is for structural autogenous bone graft harvested from the spine (larger pieces used for structural support). The choice depends on how the bone graft is processed and its intended use—20937 for bone chips/particles used to fill spaces and promote fusion, 20938 for intact pieces used for structural support.

Does CPT 20937 include bone removed during a laminectomy or decompression?

No, CPT 20937 should not be reported when bone removed during a decompression procedure (such as laminectomy) is simply saved and reused. The code requires additional harvesting work beyond what is included in the primary decompression. The bone must be deliberately harvested from another spinal structure and processed, not just incidentally obtained during the primary procedure.

What modifiers are commonly used with CPT code 20937?

The most common modifier is 59 (Distinct Procedural Service), used when 20937 might appear bundled with other procedures but represents a separate service. Modifier 76 (Repeat Procedure) may be used for rare cases of multiple distinct harvesting procedures. Modifier 51 is generally not needed as 20937 is exempt from multiple procedure reduction, though some commercial payers may have different policies.

Why would an insurance company deny CPT 20937 for medical necessity?

Payers may deny 20937 as medically unnecessary when they believe allograft (donor bone) or synthetic bone graft substitute would have been equally effective and less invasive. To prevent this denial, documentation should include patient-specific factors that make autograft preferable, such as smoking history, diabetes, previous fusion failure, young age requiring long-term fusion success, or osteoporosis affecting bone quality.