Application of a below-knee walking cast (short leg, ambulatory type) from below the knee to the toes, configured to permit weight-bearing ambulation.

Verified May 8, 2026 · 7 sources ↓

Medicare: $80.83
Total RVUs: 2.42
Global, days: 0
Region: Foot & ankle

Drawn from CMSAAPCNyspma

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify that the cast is walking/ambulatory type — documentation must distinguish from a non-walking short leg cast (29405)
Record the clinical indication: fracture (with bone(s) identified), severe ankle sprain, or other qualifying diagnosis with supporting ICD-10
Document that the provider applying the cast is NOT assuming ongoing fracture management if billing 29425 independently
Note cast material used (plaster vs. fiberglass) and configuration of the walking surface (cast shoe, footplate, rubber heel)
If same-day E&M is billed, document a separately identifiable evaluation beyond the cast application itself to support modifier 25

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

25 Significant separate E/M 51 Multiple procedures 58 Staged or related 76 Repeat, same physician LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 29425 covers applying a short leg cast — below knee to toes — specifically designed for walking. The cast bottom is configured to accept a cast shoe or is fitted with a footplate and rubber heel so the patient can bear weight and ambulate. This is what separates 29425 from 29405, which is the non-walking version of the same cast. Typical indications include stable tibial or fibular fractures, severe ankle sprains, and other lower-leg injuries where controlled ambulation is clinically appropriate.

The global period is 000, meaning there is no bundled post-op follow-up — each subsequent visit is separately billable. Cast application codes are only billable independently when the applying provider does not also assume ongoing fracture care. If the same provider applies the cast and takes on fracture management, the cast application is bundled into the fracture care code. Separately billable cast supply codes (Q4001–Q4051 series) can be added on top of 29425 for the materials, per CMS Fracture Care billing guidance.

On the same-day E&M question: if a significant, separately documented evaluation drives a decision beyond the casting itself, modifier 25 on the E&M is required. Modifier 58 applies when a staged procedure — such as transitioning from a splint at an earlier visit to a walking cast at a follow-up — is performed by the same provider.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	0.78
Practice expense RVU	1.55
Malpractice RVU	0.09
Total RVU	2.42
Medicare national rate	$80.83
Global period	0 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	$80.83
HOPD (APC 5102) Hospital outpatient department	$285.75
ASC (PI P3) Ambulatory surgical center (freestanding)	$52.03

Common denial reasons

The recurring reasons claims for CPT 29425 get rejected.

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

Bundling denial when the same provider bills 29425 and also codes the fracture care — cast application is included in fracture care codes when the provider assumes follow-up
Code mismatch: 29425 billed with a non-fracture, non-acute ICD-10 that doesn't support initial cast application
Missing modifier 25 when an E&M is billed same-day — payers bundle the visit without it
Wrong code selected: 29405 (non-walking) vs. 29425 (walking) — documentation doesn't confirm ambulatory design, triggering a downcode or denial
Modifier 58 missing when cast application at a follow-up visit was a planned stage after initial splinting by the same provider

Frequently asked questions

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

01What's the difference between 29405 and 29425?

29405 is a non-walking short leg cast. 29425 is specifically the walking or ambulatory type, configured with a cast shoe, footplate, or rubber heel to allow weight-bearing. The distinction must be documented — a generic 'short leg cast' note won't justify 29425.

02Can I bill 29425 and a fracture care code together?

No, not when the same provider applies the cast and assumes ongoing fracture management. CMS NCCI policy bundles the cast application into the fracture care code in that scenario. 29425 is independently billable only when the provider applies the cast as an initial service and does not take on follow-up fracture care.

03Can cast supplies be billed separately on top of 29425?

Yes. HCPCS Level II supply codes in the Q4001–Q4051 range are billable in addition to 29425 for the actual cast materials, per CMS Fracture Care billing guidance. The procedure code covers the application; the Q code covers the supplies.

04What modifier applies when casting follows a splint placed at a prior visit by the same provider?

Use modifier 58 on 29425. That signals the cast application is a staged or related procedure following the initial splinting — planned progression of care, not a repeat of the same service.

05Is a same-day E&M billable with 29425?

Only with modifier 25 on the E&M, and only when the visit involved a separately identifiable evaluation and decision-making beyond what's required to apply the cast. Document that work distinctly in the note.

06Does 29425 have a global period that affects subsequent visits?

The global period is 000 — there is no bundled post-op follow-up window. Each follow-up visit after the cast application is separately billable on its own merits.

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 cast type (walking/ambulatory), anatomic level (below knee to toes), weight-bearing status, walking surface configuration (cast shoe, footplate, or rubber heel), clinical indication, and whether the provider is assuming ongoing fracture management. Locking in the ambulatory designation prevents a downcode to 29405 and the bundling flags that follow when fracture care ownership is ambiguous.

See how Mira captures CPT 29425 documentation