Closed (non-surgical) treatment of a fractured sesamoid bone in the foot, using immobilization and conservative management without open surgical intervention.

Verified May 8, 2026 · 7 sources ↓

Medicare: $123.58
Work RVU: 1.08
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCMdclarityFindacodeEmedny

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Confirm closed treatment — document that no incision or open surgical approach was performed
Specify laterality (left vs. right foot) to match LT/RT modifier on the claim
Imaging findings confirming sesamoid fracture (X-ray, MRI, or CT); note the imaging modality and date
Mechanism of injury — distinguish acute traumatic fracture from stress fracture, as ICD-10 coding differs
Immobilization method used (cast, boot, stiff-soled shoe) and weight-bearing status at time of treatment
Clinical assessment of neurovascular status and any displacement of the fracture fragment

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 52 Reduced services 57 Decision for surgery 58 Staged or related 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side 50 Bilateral procedure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 28530 covers closed treatment of a sesamoid bone fracture in the foot. Sesamoids in the foot are most commonly found on the plantar surface of the first metatarsophalangeal joint, embedded within the flexor hallucis brevis tendons. Closed treatment means no incision — management typically involves immobilization (cast, boot, or stiff-soled shoe), offloading, and pain control. The companion code 28531 covers open treatment with or without internal fixation when closed management is insufficient.

The 90-day global period is the critical billing context here. Any routine follow-up, cast changes, or x-ray interpretation bundled with the visit during that window is included in the 28530 payment. If a separate, unrelated condition is managed during the global period, append modifier 24 to the E/M. If the patient returns for a related complication requiring a return procedure, use modifier 78. An unrelated procedure in the same global window takes modifier 79.

Diagnosis coding must be specific: laterality matters and payers frequently reject claims where the ICD-10 code doesn't match the LT/RT modifier. The most common ICD-10 code pairing is S92.811_ or S92.812_ (fracture of medial or lateral sesamoid of hallux), with the appropriate laterality character. Stress fractures of the sesamoid (M84.37_) code differently from acute traumatic fractures — confirm mechanism of injury in the note.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (1.08) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (3.7) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	1.08
Practice expense RVU	2.5
Malpractice RVU	0.12
Total RVU	3.7
Medicare national rate	$123.58
Global period	90 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	$123.58
HOPD (APC 5111) Hospital outpatient department	$252.01
ASC (PI P3) Ambulatory surgical center (freestanding)	$83.92

Common denial reasons

The recurring reasons claims for CPT 28530 get rejected.

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

Laterality mismatch — LT/RT modifier on the claim conflicts with the ICD-10 laterality character
ICD-10 specificity failure — using an unspecified sesamoid fracture code when a specific code for medial or lateral sesamoid is available
Stress fracture vs. acute fracture miscoding — M84.37_ and S92.8_ are not interchangeable; payers audit mechanism-of-injury documentation
Routine follow-up visits billed separately during the 90-day global period without modifier 24 or 25
Missing or inadequate imaging documentation to support the fracture diagnosis at time of initial treatment

Frequently asked questions

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

01Does 28530 include the initial X-ray interpretation?

No. Imaging interpretation is separately reportable. The 28530 global covers treatment services, not diagnostic radiology reads. Bill the appropriate radiology code separately with modifier 26 if you're providing professional interpretation only.

02Can I bill 28530 and 28531 together for the same sesamoid?

No. 28530 is closed treatment; 28531 is open treatment. They are mutually exclusive for the same sesamoid at the same encounter. Bill the one that reflects what was actually performed.

03What if both sesamoids on the same foot are fractured?

Each sesamoid is a distinct bone. Bill 28530 for each fractured sesamoid treated, appending modifier 59 to the second code to indicate a distinct procedural service. Document each fracture separately in the note.

04How do I bill if a patient in the 90-day global comes in for an unrelated sprained ankle?

Bill the E/M with modifier 24 (unrelated E/M during global period) and append the unrelated ICD-10 code. The visit must be clearly documented as addressing a condition distinct from the sesamoid fracture.

05When would modifier 22 apply to 28530?

Modifier 22 applies when the work is substantially greater than typical — for example, a markedly displaced fracture requiring prolonged manipulation attempts or unusually complex immobilization. The operative/procedure note must explicitly describe the additional time and complexity. Without that documentation, payers will deny or ignore the modifier.

06Is 28530 typically performed in the office, ED, or ASC?

Closed sesamoid fracture treatment is most commonly performed in a clinic or emergency department setting. The site-of-service differential is significant — see the Site of Service comparison table on this page for facility vs. non-facility payment rates.

Sources & references

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

Mira Scribe

Mira's AI scribe captures the fracture site (medial vs. lateral sesamoid), confirmed foot laterality, imaging modality and findings, mechanism of injury (acute trauma vs. repetitive stress), immobilization type applied, and weight-bearing instructions given. This prevents the two most common denials for 28530: a laterality mismatch between the ICD-10 code and LT/RT modifier, and an acute-vs-stress fracture miscoding that fails payer clinical edits.

See how Mira captures CPT 28530 documentation