Surgical opening of an intertarsal or tarsometatarsal joint in the foot for exploration, drainage, or removal of loose or foreign body.

Verified May 8, 2026 · 7 sources ↓

Medicare: $563.81
Total RVUs: 16.88
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCFindacodeMdclarityEmedny

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Identify the specific joint entered by anatomic name (e.g., talonavicular, calcaneocuboid, naviculocuneiform, Lisfranc/tarsometatarsal) — 'midfoot joint' alone is not sufficient.
State the indication: infection with drainage, loose body removal, foreign body retrieval, or diagnostic exploration when no less invasive option was appropriate.
Describe intraoperative findings in detail: appearance of synovium, presence and character of fluid (purulent, hemorrhagic, serous), any loose bodies or debris removed.
Document the approach and closure technique; audit teams flag operative notes that reference only a 'standard incision' without anatomic specifics.
If foreign body removal was the indication, note the nature of the foreign body and confirm it was retrieved; include any imaging correlation (e.g., pre-op X-ray or fluoroscopy confirming location).
For infection cases, document cultures obtained intraoperatively and irrigation volume/method to support medical necessity of the open approach over aspiration.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 28020 describes an arthrotomy of an intertarsal or tarsometatarsal joint — think midfoot joints such as the talonavicular, calcaneocuboid, or Lisfranc complex — performed to explore the joint space, drain infection or hemorrhage, or retrieve loose bodies or foreign material. The surgeon incises down to the joint, directly inspects the articular surfaces and synovium, and addresses whatever pathology prompted the procedure. It is not a diagnostic arthroscopy; it is an open procedure.

The 90-day global period means all routine follow-up through day 90 is bundled. If a separate, unrelated procedure is required in that window, append modifier 79. A return to the OR for a related complication (e.g., re-drainage of persistent septic joint) uses modifier 78. When 28020 is performed alongside a higher-value procedure on the same foot — such as an open calcaneus fracture repair (28415) — verify NCCI edits before billing both; the arthrotomy may be separately reportable with modifier 59 if performed at a distinct joint, but audit the edit pair first.

Site of service matters here. The HOPD rate and ASC rate differ substantially (see the Site of Service comparison table). For midfoot septic arthritis cases, the OR setting drives both patient safety and reimbursement logic — document the medical necessity for facility level of care explicitly.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	5.02
Practice expense RVU	11.16
Malpractice RVU	0.7
Total RVU	16.88
Medicare national rate	$563.81
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	$563.81
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 28020 get rejected.

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

Nonspecific joint identification in the operative note — payers and auditors require the exact joint name, not just 'foot joint' or 'midfoot.'
Bundling with a higher-value same-day foot procedure without modifier 59 establishing a distinct joint or distinct service.
Missing medical necessity documentation for the open approach when the payer expected aspiration or conservative management first.
Global period conflicts when 28020 is billed postoperatively as a staged or related return to OR without modifier 78, or as unrelated without modifier 79.
Laterality not specified — claims lacking LT or RT modifier are increasingly rejected by commercial payers and some Medicare contractors.

Frequently asked questions

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

01Which foot joints does 28020 cover?

28020 applies to intertarsal and tarsometatarsal joints — the midfoot articulations including talonavicular, calcaneocuboid, naviculocuneiform, and Lisfranc (tarsometatarsal) joints. For a metatarsophalangeal joint arthrotomy use 28022; for interphalangeal joints use 28024.

02Can 28020 be billed on the same day as an open calcaneus fracture repair (28415)?

Potentially yes, if the arthrotomy was performed at a distinct joint for a distinct purpose (e.g., subtalar joint drainage separate from the fracture repair). Check the NCCI edit pair first. If no column-1/column-2 edit bundles them, append modifier 59 or XS and document the separate joint and separate indication clearly.

03What modifier do I use for a planned second-stage irrigation and drainage of the same joint within the global period?

Modifier 58 covers a staged or therapeutically related procedure performed by the same surgeon during the global period that was planned or anticipated. Use 78 only for an unplanned return to the OR for a complication related to the original surgery.

04Is 28020 ever appropriate for a subtalar joint arthrotomy?

The subtalar joint is a posterior talocalcaneal articulation and does not map cleanly to the intertarsal joint descriptor in 28020 — though coding forums have debated this. When the operative note specifically documents the subtalar joint and no more specific code applies, 28020 is the closest match, but document the joint anatomy explicitly and be prepared to defend the code selection on audit.

05Does 28020 require laterality modifiers?

Yes for most payers. Append LT or RT to indicate which foot. If the procedure is performed bilaterally in the same session, use modifier 50 (or LT and RT on separate lines per payer preference) and expect the second side to price at 50% of the allowable.

06When is modifier 22 appropriate for 28020?

Use modifier 22 when the procedure was substantially more work than typical — for example, a severely infected joint requiring extensive debridement, multiple compartment washout, or significantly prolonged operative time. The operative note must quantify the increased complexity; 'difficult case' alone won't support it.

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 specific joint name entered (talonavicular, calcaneocuboid, tarsometatarsal, etc.), the character of fluid drained, a description of any loose or foreign bodies removed, and the intraoperative appearance of the articular surfaces — all from surgeon dictation. That prevents the single most common audit flag for 28020: an operative note that documents an open arthrotomy but fails to name the joint with enough anatomic precision to justify the code over a less invasive alternative.

See how Mira captures CPT 28020 documentation