CPT® Code 70450

Quick Reference

• Code definition: Reports a computed tomography scan of the head or brain performed without IV contrast material at any point during the study; the absence of contrast is the defining technical element.
• Key billing rule: If non-contrast sequences are acquired first and then IV contrast is administered for additional sequences in the same session, bill 70470 only. Separately billing 70450 and 70460 for a two-phase study violates NCCI PTP bundling rules and will deny automatically.
• Modifier essentials: PC/TC Indicator 1 applies [1]; use modifier 26 for the interpreting radiologist billing separately from the facility, modifier TC for the equipment owner or facility, and no modifier for global billing when the same entity provides both components. Modifier 50 (bilateral) does NOT apply to head or brain CT.
• Documentation must-have: The radiology report technique section must explicitly confirm no contrast was administered ("without IV contrast material") and must carry a final interpreting physician signature; preliminary reads are not billable under Medicare [5].
• Top confusion point: Billing 70450 when the report documents any contrast administration, or billing 70450 and 70460 as separate line items when both phases occurred in the same session. Both patterns create NCCI PTP denials and expose the claim to overpayment recoupment.
• Payer alert: CMS classifies 70450 as advanced diagnostic imaging under PAMA; ordering providers must consult a qualified Clinical Decision Support Mechanism (CDSM) and report the appropriate AUC modifier (ME, MF, MG, MH, MA, MB, MC, or MD) [8]. Traditional Medicare does not require prior authorization; Medicare Advantage plans vary and must be verified individually.
• MUE: 3 units per date of service (Date of Service Edit: Clinical, effective April 1, 2026) [2].

When to Use This Code

CPT 70450 applies when a CT scan of the head or brain is performed and no IV contrast material is administered at any point during the study. Code selection is determined by the technique section of the radiology report, not the order or clinical indication. If contrast is introduced at any point, the code changes regardless of when during the session it was given.

Clinical indications where non-contrast CT head is first-line:

• Acute head trauma and traumatic brain injury: hemorrhage appears hyperdense on non-contrast CT; contrast would obscure rather than add to hemorrhage detection
• Acute stroke triage: rule out hemorrhage before thrombolytic administration; the ACR Appropriateness Criteria rate non-contrast CT head as "Usually Appropriate" for this indication [9]
• Acute thunderclap headache: rule out subarachnoid hemorrhage
• New-onset seizure evaluation
• Altered mental status or acute neurological deficit
• Hydrocephalus and ventriculoperitoneal shunt function evaluation
• Evaluation of intracranial calcifications (best visualized without contrast)

When contrast is contraindicated, 70450 is the only viable CT head option: renal insufficiency precluding contrast, known contrast allergy without adequate premedication time, or hemodynamic instability requiring rapid imaging without delay for contrast preparation.

Provider and setting context: 70450 is payable across hospital inpatient (POS 21), hospital outpatient (POS 22), ASC (POS 24), and freestanding imaging center (POS 11, 49) settings. Payment rates differ by setting because facility and non-facility practice expense RVUs apply differently. In hospital outpatient settings, the technical component is paid under the OPPS APC system (APC Status Indicator: Codes That May Be Paid Through a Composite APC); in non-facility settings, the full MPFS non-facility rate applies [7].

Code Differentiation Table

The single most critical differentiator in the 70450 to 70470 family is contrast status within the session. Read the technique section of every report before selecting a code; do not rely on the order or the clinical indication alone.

flowchart TD
    A[CT Head Ordered] --> B{Contrast administered?}
    B -- No --> C[70450\nWithout contrast]
    B -- Yes --> D{Non-contrast phase\nperformed first?}
    D -- No --> E[70460\nWith contrast only]
    D -- Yes --> F[70470\nWithout then with contrast\nDo NOT split into 70450 plus 70460]

Billing and Modifier Rules

PC/TC Split Billing

PC/TC Indicator 1 confirms that 70450 is subject to professional and technical component billing [1]. The correct approach depends on who provides each component:

Billing both 70450-26 and 70450-TC on the same claim from the same provider constitutes duplicate billing.

Multiple Procedure Payment Reduction

70450 carries Multiple Procedures Indicator 4 [1], meaning the technical component of the lower-valued code is reduced by 50% when imaging codes from the same diagnostic imaging family (family 88) are billed on the same date. This applies to same-day billing of 70450-TC alongside 70496-TC, 70498-TC, or other family-88 imaging codes. The professional component (modifier 26) is exempt from MPPR [3].

Add-On Code

0722T (Quantitative CT tissue characterization, including interpretation and report) is a listed add-on to 70450 per CPT guidelines. Use 0722T in conjunction with 70450 when quantitative tissue characterization is performed concurrently. Do not report 0721T in conjunction with 70450 on the same anatomy; that pairing is excluded per CPT codebook guidance.

MUE: 3 per date of service [2]. Claims billing more than 3 units deny automatically at the MAC. The MUE reflects the clinical improbability of more than three separate CT head studies on a single date; documentation must establish distinct clinical justification for each unit billed above one.

Modifier 59 and X-modifiers. When 70450 is billed on the same date as another imaging service that may appear bundled, modifier 59 or the more specific XE (separate encounter), XS (separate structure), XP (separate practitioner), or XU (unusual non-overlapping service) may be necessary to establish clinical distinction. Per NCCI policy, use the most specific modifier available before defaulting to 59 [3].

Global period: XXX. The global period concept does not apply to 70450. An E&M service billed on the same date as 70450 may be reported separately when it is a significant, separately identifiable service above and beyond the work inherent in ordering and interpreting the imaging study; modifier 25 applies to the E&M code, not to 70450.

Documentation Essentials

Required elements in the radiology interpretation report:

1. Clinical indication stating the ordering diagnosis or reason for the study
2. Technique statement explicitly confirming no contrast was administered (e.g., "CT of the brain was performed without IV contrast material")
3. Systematic findings: brain parenchyma, ventricular system, sulci, extra-axial spaces, calvarium, skull base, visualized soft tissues
4. Impression with the radiologist's diagnosis or differential diagnosis
5. Interpreting physician signature and date of final interpretation

CMS requires a valid written or electronic order from the treating provider prior to the study; verbal-only orders are insufficient for Medicare billing [5].

Audit red flags specific to 70450:

• Technique section omits contrast status: without explicit documentation confirming no contrast was given, auditors will question whether 70460 or 70470 was the appropriate code; this drives code-to-documentation mismatch findings
• Preliminary or unsigned reads: Medicare requires a final signed interpretation; wet reads and attestation-pending reports do not support payment [5]
• ICD-10-CM mismatch: a diagnosis code that does not clinically align with CT head imaging (e.g., lumbar pain without neurological signs, routine screening without documented clinical indication) triggers medical necessity denial
• Same-date duplicate imaging without distinct clinical justification: RAC reviewers flag repeat 70450 claims on the same date without separately documented clinical reasons for each study

Medical necessity and LCD criteria:

CMS has not issued a National Coverage Determination for CT head or brain [6]. Coverage is governed by the Medicare reasonable and necessary standard under Social Security Act §1862(a)(1)(A). Local Coverage Determinations are MAC-specific; providers must search the CMS Medicare Coverage Database by HCPCS code 70450 for the applicable MAC jurisdiction (Noridian, Novitas, CGS, WPS, Palmetto GBA, or NGS). Vague ICD-10-CM codes such as R51.9 (Headache, unspecified) for routine chronic headache without documented red flags may not satisfy LCD criteria; the ordering physician's record must establish the clinical necessity for advanced imaging.

Medicare, Commercial and Medicaid Payer Rules

Medicare

No NCD governs 70450 [6]; coverage is MAC-specific. Traditional Medicare does not require prior authorization. The MUE is 3 per date of service [2].

2026 MPFS national payment rates before geographic adjustment [1]:

The 2026 conversion factor of $33.4009 represents approximately a 3.3% increase over 2025, partially offsetting the minor RVU reduction (work RVU decreased from 0.85 to 0.83) [1].

In hospital outpatient settings, the TC is paid under OPPS as a Composite APC; in ASC settings, 70450 is paid as a radiology service based on OPPS relative payment weight [7]. Place of service selection directly affects payment rate; billing non-facility practice expense RVUs for a study performed in a hospital creates overpayment and recoupment risk.

BETOS classification I2A (Advanced imaging: CAT/CT/CTA brain/head/neck) and CCS Classification 177 (CT scan head) govern how CMS and quality programs categorize and benchmark utilization of this code.

AUC/PAMA: All three CT head codes (70450, 70460, 70470) are classified as advanced diagnostic imaging under PAMA. Ordering providers must consult a qualified CDSM and document the consultation outcome on the claim using the appropriate AUC modifier [8]. CMS continues phased implementation; monitor cms.gov for the full enforcement timeline.

Commercial Payers

Commercial payers generally follow CPT coding conventions for 70450. Key distinctions from Medicare:

• Prior authorization requirements vary significantly; Medicare Advantage plans may require PA even though traditional Medicare does not. Verify each MA plan before scheduling to prevent claim denial for missing authorization.
• Some commercial payers apply automated edits that downcode 70450 to a lower-reimbursed code when specific diagnosis codes are submitted; review payer local medical review policies before submitting.
• Some commercial contracts bundle professional and technical components under a single payment rate rather than honoring the PC/TC split; confirm contract terms before billing separately.

Medicaid

Medicaid coverage for 70450 is state-specific. Managed Medicaid plans may impose prior authorization requirements, frequency caps, or preferred provider restrictions for advanced diagnostic imaging. Verify applicable state Medicaid policy and managed care plan requirements prior to service.

Common Denials and Prevention

Contrast mismatch between code and report The radiology report documents contrast administration but 70450 was billed, or the report confirms no contrast but 70460 was submitted. This documentation-to-claim mismatch is identified on post-payment medical review and triggers both denial and overpayment assessment. Prevention: Read the technique section of every radiology report before selecting the code. Do not code from the order or the clinical indication; only the report governs contrast status.

NCCI PTP bundling: 70450 and 70460 billed same date for same session Billing both 70450 and 70460 for a two-phase study triggers an automatic NCCI PTP denial; both codes are components of 70470 when performed sequentially in a single session [3]. Prevention: When both non-contrast and post-contrast sequences appear in the same report for the same session, bill 70470 only. If two genuinely distinct studies were performed at different times of day for separate clinical reasons, modifier XE with supporting documentation may establish a distinct encounter; verify payer policy before appending.

Missing or unsigned interpretation report Medicare requires a final signed interpretation; claims where only a preliminary read or unsigned attestation exists in the record will deny on medical review [5]. Prevention: Implement a billing hold for radiology claims until the final signed report is confirmed in the EHR or RIS. Do not bill from preliminary reads or dictation-pending status.

Medical necessity denial: unsupported ICD-10-CM R51.9 (Headache, unspecified) or other vague diagnosis codes submitted without supporting clinical documentation may not satisfy MAC LCD criteria for advanced diagnostic imaging [6]. Prevention: Query the ordering provider for specificity when the documentation supports a more precise diagnosis. The ordering physician's clinical note must document the clinical indication (sudden onset, neurological signs, or other red flags) and the diagnosis code must accurately reflect that documented indication. If the record does not support medical necessity for CT head, the claim is at risk for denial regardless of whether the study was performed.

MUE exceeded Billing more than 3 units of 70450 on the same date triggers automatic denial at the MUE threshold [2]. Prevention: Claims requiring more than 3 units require contemporaneous documentation of distinct clinical justification for each separate study. Contact the MAC prior to submission for claims that may approach this threshold.

Coding Scenarios

Scenario 1: Acute Ischemic Stroke Protocol A 68-year-old presents to the ED with sudden onset left-sided hemiplegia. The emergency physician orders a stat CT head without contrast, followed immediately by CTA head and CTA neck as part of a large vessel occlusion protocol. CT head shows no hemorrhage; CTA head demonstrates M2 occlusion.

Correct coding: 70450-TC + 70496-TC + 70498-TC (hospital billing); radiologist bills 70450-26 + 70496-26 + 70498-26. Diagnosis: I63.9.

Why: 70450 (non-contrast CT head), 70496 (CTA head), and 70498 (CTA neck) are distinct studies serving different diagnostic purposes and are separately reportable. MPPR applies to the TC side: the lowest-valued TC code is reduced by 50% under diagnostic imaging family 88 rules [3]. The professional components are not subject to MPPR. Do not use 70470 here; the CTA codes use contrast for vascular imaging, which is a separate clinical function from the non-contrast CT head, not a continuation of the same study.

Scenario 2: Two-Phase Study Misidentified as Separate Codes A neurologist orders CT head for a patient with known lung cancer and new confusion. The radiologist acquires non-contrast sequences, then administers IV contrast and acquires post-contrast sequences in the same session to evaluate for brain metastases.

Correct coding: 70470 only. Diagnosis: C71.9.

Why: Both phases were performed in a single session; 70470 captures the complete two-phase study. Separately billing 70450 and 70460 violates NCCI PTP bundling rules and generates automatic denial [3]. Had only post-contrast images been acquired with no prior non-contrast phase, 70460 would apply; had only non-contrast images been acquired, 70450 would apply.

Scenario 3: Freestanding Imaging Center with Global Billing A 34-year-old with new-onset tonic-clonic seizures is referred by neurology for outpatient CT head without contrast. The study is performed and interpreted at a freestanding imaging center where the radiologist is an owner-employee who interprets all studies performed on site.

Correct coding: 70450 (global, no modifier). Diagnosis: G40.909.

Why: The same entity provides both the technical service (equipment, technologist, PACS) and the professional interpretation; global billing applies and is the only correct approach. Splitting into 70450-26 and 70450-TC from the same practice constitutes duplicate billing. Approximate 2026 non-facility payment: $106.55 (3.19 total RVU x $33.4009 conversion factor) [1].

Scenario 4: Headache with Medical Necessity Risk A PCP orders CT head for a 55-year-old with chronic daily headaches unresponsive to NSAIDs. No neurological deficits, no sudden onset, no fever. Study is normal. Claim is submitted with R51.9.

Correct coding: 70450 if performed; however, R51.9 alone for chronic headache without documented red flags carries substantial medical necessity denial risk. If the clinical record supports migraine, use G43.909.

Why: R51.9 for routine chronic headache without red flags (thunderclap onset, neurological signs, papilledema, fever, age-related vascular risk) may not satisfy MAC LCD criteria for advanced diagnostic imaging [6]. The ordering physician's note must document the clinical justification for CT head specifically; absence of that documentation leaves the claim vulnerable regardless of whether the study was completed.

Related Codes

• 70460: CT head/brain with contrast; use when IV contrast is administered before scanning and no non-contrast phase is performed
• 70470: CT head/brain without then with contrast; replaces separate billing of 70450 and 70460 when both phases occur in the same session
• 70496: CTA head; separately reportable when vascular imaging is performed on the same date as 70450, as in acute stroke protocol
• 70498: CTA neck; frequently paired with 70450 and 70496 in comprehensive stroke workup
• 70551: MRI brain without contrast; alternative modality preferred for white matter disease, MS, subacute infarct, or tumor characterization
• 70553: MRI brain without then with contrast; comprehensive brain tumor, abscess, or demyelinating disease evaluation
• 76376: 3D rendering without independent workstation; may be separately reportable when performed with 70450; verify with payer LCD
• 76377: 3D rendering with independent workstation; may be separately reportable when performed with 70450; verify with payer LCD
• 0722T: Quantitative CT tissue characterization; add-on to 70450 when performed concurrently
• S06.0X0A: Concussion without loss of consciousness, initial encounter; common diagnosis pairing for head trauma CT
• I63.9: Cerebral infarction, unspecified; primary diagnosis for acute ischemic stroke CT head workup
• G45.9: Transient ischemic attack, unspecified; common pairing for acute neurological deficit imaging

Sources

1. CMS 2026 National Physician Fee Schedule Relative Value File: 2026 RVUs, conversion factor ($33.4009), PC/TC indicator, multiple procedure indicator, and global period for 70450, 70460, and 70470.
2. CMS NCCI Medically Unlikely Edits, Practitioner Services, effective April 1, 2026: MUE values for 70450 (3), 70460 (1), and 70470 (2).
3. CMS NCCI Policy Manual for Medicare Services, 2026: Bundling rules, PTP edit principles, and multiple procedure reduction rules for diagnostic imaging.
4. CMS Internet Only Manual, Publication 100-02, Chapter 15, §80: Coverage standard for radiology services and §80.6 diagnostic test documentation requirements.
5. CMS Internet Only Manual, Publication 100-04, Chapter 13: Radiology services claims processing requirements and denial reasons.
6. CMS Medicare Coverage Database: No NCD for CT head confirmed; MAC LCD lookup by jurisdiction.
7. CMS Hospital Outpatient Prospective Payment System, 2026: APC payment for 70450-TC in hospital outpatient settings.
8. CMS Appropriate Use Criteria for Advanced Diagnostic Imaging (PAMA): AUC consultation requirements for ordering 70450, 70460, and 70470.
9. ACR Appropriateness Criteria: Clinical indications and imaging appropriateness ratings for CT head by clinical scenario.