Glossary · Clinical

X-ray (plain radiograph)

A plain radiograph (x-ray) is a two-dimensional image produced by passing ionizing radiation through the body and capturing the result on a digital detector or film. It is the first-line imaging study in orthopedics for evaluating bone alignment, fractures, joint-space narrowing, and hardware positioning.

Verified May 8, 2026 · 6 sources ↓

Drawn from CMSAAPCRadiologytoday

Definition

Source · Editorial summary grounded in 6 cited references ↓

Plain radiographs use differential x-ray absorption across tissues—bone attenuates more radiation than soft tissue—to produce static images that reveal cortical and trabecular bone architecture, joint congruency, and implant position. In orthopedic practice, the number of views ordered per session is clinically significant: a single anteroposterior projection is coded differently from a complete multi-view series, and the CPT code selected must match the actual number of views obtained and interpreted, not the number ordered. Digital radiography (DR) is now the standard acquisition method; computed radiography (CR) and legacy film-based imaging carry separate billing implications, including Medicare payment reductions under modifier FX for film-based claims.

Orthopedic plain-film series are laterality-specific and view-count-specific. For example, a unilateral knee study with one or two views maps to a different CPT code than a complete knee series with four or more views or a bilateral standing knee study. Getting the code right at the point of documentation—not at the billing desk—prevents both undercoding (lost revenue) and overcoding (audit exposure). When a radiograph is taken before and after fracture reduction, each session is separately reportable using the appropriate repeat-procedure modifier.

At independent diagnostic testing facilities (IDTFs), plain radiographs of orthopedic structures require supervision by a radiologist or orthopedic surgeon and must be performed by a certified radiologic technologist (ARRT RT-R). When the ordering orthopedist does not own the imaging equipment, only the professional component (modifier 26) is billable by that practice; the technical component (modifier TC) belongs to the facility that owns and operates the equipment. A separate, signed radiology report must exist before any professional-component claim is submitted.

Why it matters

Incorrect view-count coding is one of the highest-frequency denial triggers in orthopedic radiology billing. Reporting a complete four-or-more-view knee code when only two views were obtained—or vice versa—exposes the practice to payer audit and potential recoupment. Equally, billing modifier 26 on a reread of films that were already interpreted by a referring provider (e.g., an ED radiologist) constitutes duplicate billing; that work belongs inside the E/M medical-decision-making component, not on a standalone radiology line, unless the orthopedist identifies a finding not present in the original report and appends modifiers 26 and 77 on the same date of service.

Common mistakes

Where people most often go wrong with this concept.

Source · Editorial brief grounded in cited references ↓

Selecting a higher view-count CPT code (e.g., 73564 for four-or-more knee views) when documentation supports only two views (73560), inflating the claim.
Billing the full radiology code without modifier 26 or TC when the practice does not own the imaging equipment, causing the facility's TC claim and the practice's claim to overlap.
Submitting a separate modifier-26 line for a routine reread of films already interpreted by a referring physician, rather than incorporating that review into the E/M medical-decision-making.
Failing to append modifier 76 (repeat procedure, same provider) to the postreduction x-ray when the same number of views was obtained pre- and postreduction by the same interpreting provider.
Appending modifier 77 (repeat procedure, different provider) on a date of service different from the original study—modifier 77 is only valid when the repeat occurs on the same calendar date.
Reporting individual radiograph codes alongside a bone study series (e.g., CPT 77073 for bone-length studies) when those individual images are already bundled into the series code under NCCI policy.
Not including modifier FX on film-based x-ray claims submitted to Medicare, resulting in claim rejection or missed payment reduction notices.
Omitting laterality documentation (left, right, or bilateral) in the order and report, making it impossible to defend the correct CPT code during an audit.

Related codes

Codes commonly involved when this concept appears in practice.

CPT

ICD-10

M17.11 M16.11

Modifiers

26 Professional component 76 Repeat procedure same physician 77 Repeat procedure another physician 59 Distinct procedural service LT Left side RT Right side

Frequently asked questions

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

01Can an orthopedic practice bill a separate x-ray code when the physician reviews films that were already read by an ED radiologist?

Generally no. When a formal radiology report already exists from the referring provider, the orthopedist's review of those films is part of E/M medical-decision-making and cannot be billed separately with modifier 26. The only exception is when the orthopedist identifies a clinically significant finding—such as a fracture—absent from the original report, in which case the appropriate x-ray CPT code with modifiers 26 and 77 may be submitted with supporting documentation, but only if the reread occurs on the same date of service as the original study.

02What is the difference between modifier 76 and modifier 77 for postreduction x-rays?

Modifier 76 signals a repeat procedure performed and interpreted by the same provider as the original study. Modifier 77 signals a repeat procedure interpreted by a different provider, and it applies only when both studies occur on the same calendar date. If the view counts differ between the pre- and postreduction series, modifier 59 is used instead to identify each as a distinct service.

03When should an orthopedic practice bill modifier 26 versus the full x-ray CPT code?

Modifier 26 (professional component) is used when the practice interprets the x-ray but does not own or operate the imaging equipment. The facility that owns the equipment bills the same CPT code with modifier TC (technical component). If the practice owns the equipment and performs both acquisition and interpretation, the full CPT code is billed without splitting modifiers.

04Does Medicare pay less for film-based x-rays than for digital radiographs?

Yes. Medicare applies a payment reduction to x-rays acquired on film. Practices must append modifier FX to film-based radiograph claims submitted to Medicare; failure to do so results in claim adjustment under CARC 237 and RARC N775. Digital radiography—whether direct digital or computed radiography—is subject to its own payment rules and transition incentives.

05Can a bone-length study (CPT 77073) be billed alongside the individual hip or knee radiographs obtained during the same session?

Not without a distinct procedural modifier. Under NCCI bundling policy, bone study series codes such as 77073 include the radiographs obtained as part of that series. Reporting individual radiograph codes on top of the bone study code is considered unbundling. If a separately identifiable, clinically independent radiograph was also obtained in the same session, modifier 59 must be appended and supported by documentation.

Sources & references

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

Mira AI Scribe

When documenting a plain radiograph encounter for orthopedic billing, Mira captures three variables that determine the correct CPT code: (1) anatomic site with confirmed laterality (left, right, or bilateral); (2) exact number of views obtained and interpreted, not merely ordered; and (3) whether the study is a new acquisition or a reread of films from another provider. For new acquisitions, Mira selects the view-count-specific CPT code (e.g., 73560 for one-to-two knee views vs. 73564 for four-or-more views) and flags whether the practice owns the equipment to determine whether modifier 26 alone or the full code is appropriate. For postreduction films, Mira prompts for the interpreting provider identity and view count to apply modifier 76 (same provider, same view count), modifier 59 (same provider, different view count), or modifier 77 (different provider, same date). When a patient presents with pre-existing outside films and an accompanying report, Mira routes the radiograph review to the E/M medical-decision-making data element rather than generating a standalone radiology line, preventing duplicate-billing exposure. If the orthopedist identifies a previously unreported finding in those outside films, Mira surfaces the option to append modifiers 26 and 77 and prompts for supporting chart documentation before the claim is submitted. For Medicare claims, Mira checks acquisition method and appends modifier FX automatically when film-based imaging is documented.

See Mira's approach

Related terms

Fluoroscopy (image guidance) Clinical

Fluoroscopy is real-time X-ray imaging used during orthopedic procedures to guide needle placement, confirm fracture reduction, direct implant positioning, and assess joint congruency—without interrupting the surgical workflow.

MRI (magnetic resonance imaging) Clinical

MRI (magnetic resonance imaging) is a non-ionizing diagnostic imaging modality that uses strong magnetic fields and radiofrequency pulses to generate high-contrast images of soft tissues, joints, and the spine. In orthopedics, it is the primary tool for evaluating cartilage, ligaments, tendons, bone marrow, and nerves when plain radiographs are insufficient.

NCCI (National Correct Coding Initiative) Coding

The National Correct Coding Initiative (NCCI) is a CMS program of automated prepayment edits that prevent Medicare and Medicaid from paying for procedure code combinations that are incorrectly billed together or billed in quantities that exceed what is clinically reasonable.