20551

Injection of a therapeutic substance into the origin or insertion point of a single tendon, used to treat tendinitis, enthesopathy, or localized inflammation at the bone-tendon junction.

Verified May 8, 2026 · 6 sources ↓

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

Drawn from CMSFindacodeAAPCFastrvu

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specific tendon origin or insertion treated, identified by name (e.g., lateral epicondyle, Achilles insertion, patellar origin)
Substance injected, concentration, and dosage administered
Clinical indication — diagnosis driving the injection (e.g., lateral epicondylitis, Achilles enthesopathy)
Technique and approach used for needle placement
Patient response immediately post-procedure and any adverse reactions
For more than three injections to the same site within six months: explicit justification in the chart explaining why additional injections are medically necessary
If imaging guidance was used, separate documentation supporting that service and which guidance code was billed

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 LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

20551 covers a therapeutic injection delivered directly at a tendon's origin or insertion — where the tendon attaches to bone. Classic examples: corticosteroid injection at the lateral epicondyle for lateral epicondylitis (tennis elbow), or at the medial epicondyle for golfer's elbow. The key anatomic distinction from 20550 is that 20551 targets the enthesis, not the tendon sheath. If the physician injects the sheath, bill 20550. If the physician injects a joint or bursa, use 20600–20611. Getting this wrong is the most common coding error in this family.

The global period is 000, meaning no pre- or post-operative services are bundled. Each session stands alone. Bill one unit of 20551 per tendon injected. If a second distinct tendon origin or insertion is injected in the same session, report an additional 20551 with modifier 59 or XS to identify it as a separate site — do not stack units on a single line. Imaging guidance is not included in 20551; if ultrasound or fluoroscopic guidance is used, report 76942, 77002, or 77021 separately.

CMS LCD policy (Articles A57201 and A57079) flags a specific threshold: more than three injections to the same site or local area within a six-month period require explicit chart justification. Auditors will pull those records. Document why conservative measures failed, why the diagnosis remains accurate, and why continued injection therapy is appropriate. Plantar fasciitis injections go on 20550, not 20551 — even when a calcaneal spur is also targeted; CMS policy directs that combined plantar fascia/calcaneal spur injections use a single 20551.

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	1
Malpractice RVU	0.08
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)	$33.57

Common denial reasons

The recurring reasons claims for CPT 20551 get rejected.

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

Wrong code selection — 20551 billed when injection was into the tendon sheath (correct code: 20550) or a joint/bursa (correct code: 20600–20611)
Missing or vague documentation of the specific tendon site — notes that say 'elbow injection' without naming the tendon origin trigger medical necessity denials
Exceeding three injections to the same site in six months without chart justification for continued treatment
Imaging guidance bundled into 20551 rather than reported separately with the applicable guidance code
Units stacked on a single claim line when multiple tendons were injected — each distinct tendon requires a separate 20551 line with modifier 59 or XS

Frequently asked questions

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

01What's the difference between 20550 and 20551?

Site of injection determines the code. 20550 is for the tendon sheath, ligament, or aponeurosis. 20551 is for the tendon origin or insertion — where tendon meets bone. If the physician injects the sheath of the Achilles, that's 20550. If the physician injects at the Achilles insertion on the calcaneus, that's 20551. Confusing the two is the most frequent error in this code family.

02Can I bill two units of 20551 when two tendons are injected in the same session?

Report a separate line for each tendon, not two units on one line. Append modifier 59 or XS to the second (and any subsequent) line to identify each as a distinct procedural service. Stacking units on one line causes claim processing errors and can trigger medical review.

03Does 20551 include imaging guidance?

No. Imaging guidance is never bundled into 20551. If ultrasound guidance is used, report 76942 separately. Fluoroscopic guidance is reported with 77002. The imaging code requires its own documentation, including a permanent image record and interpretation note.

04How do I bill bilateral tendon injections — modifier 50 or separate RT/LT lines?

Payer preference varies. Medicare and most commercial payers accept either modifier 50 on a single line or separate lines with RT and LT. Check your MAC's local preference. Either way, document both sides explicitly in the procedure note — bilateral intent must be in the chart, not just on the claim.

05What happens if my patient needs a fourth injection to the same site within six months?

CMS policy (Articles A57201/A57079) requires explicit chart justification for any injection beyond three to the same site or local area within a six-month window. Document why the diagnosis is still correct, why prior injections provided incomplete relief, and why continued injection is appropriate over alternative treatment. Without that documentation, the claim is audit-vulnerable.

06Is plantar fasciitis injected under 20551 or 20550?

20550. Plantar fasciitis maps to 20550 with ICD-10 M72.2. CMS policy also specifies that an injection covering both the plantar fascia and a calcaneal spur is still reported as a single 20551 — not a separate 20550 plus 20551 combination.

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 tendon name, anatomic attachment site (origin vs. insertion), injected substance with dose, and the clinical indication from dictation. It flags notes that reference a generic site like 'elbow' without naming the specific tendon, which is the documentation gap auditors and payers most commonly cite when denying 20551 claims for lack of medical necessity.

See how Mira captures CPT 20551 documentation