Imaging · Knee

Radiologic examination of the knee consisting of four or more views, including oblique and tunnel projections, for a complete diagnostic workup.

Verified May 8, 2026 · 7 sources ↓

Medicare: $49.43
Total RVUs: 1.48
Global, days
Region: Knee

Drawn from CMSEmblemhealthAAPC

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Ordering physician's written or electronic order specifying the knee, laterality, and clinical indication
Radiology report naming each view obtained (e.g., AP, lateral, oblique, tunnel/notch) — generic 'complete series' language is an audit flag
Documented medical necessity tied to an ICD-10 diagnosis code (e.g., M17.11 primary OA right knee, M25.561 right knee pain, S80–S89 range for trauma)
Laterality clearly identified in both the order and the report; absence triggers payer LT/RT modifier denial
For bilateral studies: separate documentation supporting a diagnostic — not merely comparative — indication for each knee
Interpreter attestation and final signed report for professional component billing under modifier 26

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

26 Professional component 52 Reduced services 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

73564 covers a complete knee X-ray series of four or more views — typically anteroposterior, lateral, oblique, and tunnel (notch) projections. The tunnel view is what distinguishes this code from 73562 (three views); it opens the intercondylar notch and is essential for evaluating loose bodies, osteochondral defects, and early joint space narrowing not visible on standard AP/lateral. Ordering physicians in orthopedics and sports medicine lean on this series for osteoarthritis staging, pre-op planning, and post-op hardware assessment.

The code sits in the knee imaging family alongside 73560 (1–2 views), 73562 (3 views), and 73565 (bilateral standing AP). Do not stack 73564 with 73565 on the same claim for the same knee — payers including EmblemHealth explicitly deny that combination when modifiers are identical or absent. If the contralateral knee is imaged only for comparison and the order doesn't specify a diagnostic indication for that side, bill the symptomatic side only (e.g., 73564-LT); the comparison side does not generate a separate billable unit.

For bilateral diagnostic studies where both sides are independently ordered and documented, append LT and RT on separate lines. The professional component (modifier 26) and technical component (modifier TC) split applies when the reading physician and the facility are billing separately — common in hospital outpatient and independent imaging center settings.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	0.21
Practice expense RVU	1.25
Malpractice RVU	0.02
Total RVU	1.48
Medicare national rate	$49.43
Global period	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	$49.43
HOPD (APC 5522) Hospital outpatient department	$106.81

Common denial reasons

The recurring reasons claims for CPT 73564 get rejected.

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

Missing LT or RT modifier — several commercial payers require laterality on all unilateral extremity imaging codes
73564 billed same-day as 73565 with matching or absent modifiers; payers bundle or deny the lower-value code per radiology bundling policy
Diagnosis code doesn't support medical necessity — screening-only or Z-code diagnoses without a clinical symptom or condition are frequently rejected under NCD/LCD coverage rules
Fewer than four views documented in the report while 73564 is billed — downcoding to 73562 on audit
Comparison-side knee billed as a second unit without an independent diagnostic order or separate clinical indication documented for that side

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01What's the minimum number of views to bill 73564 instead of 73562?

Four views. If the report documents only three — even if the order requested more — bill 73562. The view count in the signed report controls the code selection, not the order.

02Can 73564 and 73565 be billed on the same date for the same patient?

Generally no. Payers treat 73565 (bilateral standing AP) as bundled into or duplicative of 73564 when billed on the same date with the same or absent modifiers. If the studies are truly distinct and separately documented, modifier 59 or XS may apply, but expect scrutiny and verify with the specific payer before submitting.

03When should modifier 26 be appended to 73564?

Append modifier 26 when the reading physician bills only for interpretation — no ownership or control of the equipment. The facility or imaging center bills the technical component (TC) separately. In a fully physician-owned office with in-house X-ray, bill the global code without either modifier.

04A commercial payer denied 73564 billed with M25.561 (right knee pain) and demanded a modifier. Which modifier applies?

The payer is most likely requiring laterality. Resubmit with modifier RT appended. Some commercial plans have a system edit that rejects unilateral extremity imaging codes without a side modifier, even when the diagnosis code itself specifies the side.

05If a patient has bilateral knee OA and the physician orders a full series on each knee the same day, how do you bill?

Bill 73564-LT and 73564-RT on separate lines — not modifier 50, which is designed for surgical procedures. Each line needs its own laterality-specific ICD-10 code and the operative report (or radiology order) must independently justify each side as diagnostic, not comparative.

06What's the difference between 73564 and 73565, and when does 73565 apply?

73565 is specifically a bilateral standing anteroposterior view used to assess weight-bearing joint space — one image, both knees. It does not replace 73564; it answers a different clinical question. If the physician orders a full four-view unilateral series plus a bilateral standing AP for weight-bearing comparison, you have a potential multi-code scenario that requires careful modifier and bundling review before billing both.

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 number and type of views dictated (AP, lateral, oblique, tunnel/notch), the laterality, and the clinical indication driving the order. That prevents the two most common denials for 73564: a missing LT/RT modifier and a mismatch between views documented and the four-or-more-view threshold the code requires. If the dictation references a contralateral comparison view, the scribe flags whether a separate diagnostic order exists so you don't overbill the second side.

See how Mira captures CPT 73564 documentation