20550

Injection into a single tendon sheath, ligament, or aponeurosis (such as the plantar fascia) — one anatomical site per unit.

Verified May 8, 2026 · 6 sources ↓

Medicare: $60.46
Total RVUs: 1.81
Global, days: 0
Region: General

Drawn from CMSAAPCKzanow

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify the exact anatomical site injected — e.g., flexor tendon sheath of the index finger or plantar fascia; 'tendon injection' alone is insufficient.
Document the substance injected (corticosteroid name and dose, anesthetic agent, or combination) and the volume administered.
State the clinical indication and supporting diagnosis code — medical necessity must be explicit in the note, not inferred.
If multiple injections were performed, identify each site separately and confirm distinct anatomical locations to support modifier 59 or XS.
If ultrasound guidance was used, document real-time imaging, record storage of the permanent image, and note the guidance in the procedure description.
Distinguish whether the injection targeted the tendon sheath versus the tendon origin/insertion — this determines 20550 vs. 20551 and must be explicit.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

50 Bilateral procedure 51 Multiple procedures 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 XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 20550 covers a therapeutic injection — typically corticosteroid, anesthetic, or a combination — delivered into a tendon sheath, ligament, or aponeurosis. Classic examples include trigger finger injections into the flexor tendon sheath and plantar fasciitis injections into the plantar fascia. The code represents one injection site, not one injection per tendon. If the provider injects multiple distinct anatomical sites in the same session, bill additional units with modifier 59 or XS — not modifier 50, which applies only to bilateral same-structure injections.

The 20550 vs. 20551 distinction trips up claims constantly. Use 20550 for the tendon sheath or ligament body; use 20551 when the needle targets the tendon's origin or insertion. For calcaneal spur injections, or any injection spanning both the plantar fascia and a calcaneal spur, CMS explicitly requires 20551 — not 20550. Morton's neuroma injections don't belong under 20550 at all; use 64455 or 64632 per CMS LCD guidance.

The global period is 000, so no post-procedure visits are bundled. If you're using ultrasound guidance to target the injection, bill 76942 separately — but document the medical necessity for guidance and capture the image in the record. Injections into a joint or bursa belong under the 20600–20611 series, not 20550.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	0.73
Practice expense RVU	0.99
Malpractice RVU	0.09
Total RVU	1.81
Medicare national rate	$60.46
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	$60.46
HOPD (APC 5441) Hospital outpatient department	$313.60
ASC (PI P3) Ambulatory surgical center (freestanding)	$33.23

Common denial reasons

The recurring reasons claims for CPT 20550 get rejected.

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

Wrong code for injection site: 20550 used when needle targeted tendon origin or insertion — that's 20551 territory.
Morton's neuroma injections billed under 20550 instead of the required 64455 or 64632 per CMS LCD A57079.
Multiple same-day injections billed as additional 20550 units without modifier 59 or XS, triggering NCCI bundling edits.
Diagnosis code doesn't match the injected structure — e.g., a joint diagnosis paired with a tendon sheath injection code.
Ultrasound guidance (76942) denied because operative note lacks documentation of real-time imaging or permanent image storage.
Modifier 50 applied to a unilateral injection or to 20551 — CMS allows modifier 50 with 20550 but not with 20551; conflating the two codes causes rejections.

Frequently asked questions

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

01What's the difference between 20550 and 20551?

20550 is for the tendon sheath, ligament, or aponeurosis. 20551 is for the tendon's origin or insertion point. The needle destination in the operative or procedure note determines which code applies — they are not interchangeable.

02Can I bill 20550 for a plantar fasciitis injection?

Yes. CMS explicitly confirms that plantar fasciitis injections are addressed by 20550. If the injection also covers a calcaneal spur, CMS requires 20551 instead — not 20550, and not both codes together.

03Can 20550 and 20551 be billed on the same day?

Only if injections were performed at genuinely distinct anatomical sites — one into a tendon sheath and a separate one into a tendon origin or insertion. Append modifier 59 or XS and document each site individually. Billing both for the same foot structure is incorrect.

04How do I bill for bilateral tendon sheath injections on the same day?

Append modifier 50 to 20550 when the identical procedure is performed bilaterally. CMS permits modifier 50 with 20550. Document both sides clearly in the note.

05Is Morton's neuroma correctly billed under 20550?

No. CMS LCD A57079 is explicit: Morton's neuroma injections do not involve the structures described by 20550. Use 64455 or 64632 for those injections. Using 20550 for Morton's neuroma will trigger a denial.

06Can ultrasound guidance be billed with 20550?

Yes — bill 76942 separately when guidance is used. The note must document real-time imaging and permanent image storage. Without that documentation, the guidance code will be denied.

07How many times can 20550 be billed in a single session?

One unit per distinct anatomical site. The code is not reported per tendon. If two separate sites are injected, bill a second unit with modifier 59 or XS and document each site by name.

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 injected structure by name (tendon sheath, ligament, or aponeurosis), the exact anatomical location, the agent and dose injected, and whether ultrasound guidance was used. That specificity prevents the two most common 20550 denials: upcoding to 20551 when the sheath — not the origin/insertion — was targeted, and missing documentation for separately billed guidance.

See how Mira captures CPT 20550 documentation