M67.00

Acquired shortening of the Achilles tendon at an unspecified ankle, classified under other disorders of synovium and tendon. Use only when the affected side is not documented.

Verified May 8, 2026 · 5 sources ↓

Status: Billable
Chapter: 13
Related CPT: 5
Region: Foot & ankle

Drawn from CDCICD10DataAAPCCMS

Documentation tips

What should appear in the chart to support M67.00.

Source · Editorial brief grounded in 5 cited references ↓

Document laterality explicitly (right or left ankle) in every encounter note to allow coding to M67.01 or M67.02 — M67.00 should be a last resort when side is genuinely unknown.
Record the acquired etiology: prior injury, surgical history, prolonged immobilization, or neurological condition to distinguish from congenital shortening.
Document ankle dorsiflexion range of motion with the knee extended and flexed (Silfverskiöld test) to support clinical severity and justify physical therapy or procedural intervention.
If imaging (ultrasound or MRI) was obtained, include findings on tendon length, thickness, and any associated changes in the note.
Capture any conservative care history (stretching, orthosis, PT) before surgical procedures to establish medical necessity for intervention.

Related CPT procedures

Procedure codes commonly billed with M67.00. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

27685 $681.71

Surgical lengthening or shortening of a single tendon in the lower leg or ankle to correct contracture, acquired deformity, or functional impairment.

27687 $434.21

Surgical lengthening of the gastrocnemius muscle at its aponeurosis to relieve equinus contracture and restore ankle dorsiflexion — classically performed as the open Strayer procedure.

97110 $29.06

Therapeutic exercise billed per 15-minute unit, targeting strength, endurance, range of motion, or flexibility with direct one-on-one patient contact.

20550 $60.46

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

97530 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M67.00 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

Using M67.00 when the chart clearly documents right or left ankle — drop to M67.01 or M67.02; payers including CMS home health and injection LCDs do not list M67.00 as a covered code.
Coding M67.00 for congenital Achilles contracture — the 'acquired' designation is mandatory; congenital short Achilles tendon is classified elsewhere.
Confusing acquired Achilles shortening with Achilles tendinitis (M65.27x) — shortening is a structural contracture, not an inflammatory condition; the codes are not interchangeable.
Billing M67.00 alongside acute Achilles injury S-codes without confirming these represent distinct, co-existing diagnoses rather than the same pathology.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M67.00 captures non-congenital Achilles tendon contracture when the operative note, clinic note, or imaging report does not specify right or left. The 'acquired' qualifier is critical — this code does not apply to congenital short Achilles tendon (which falls outside M67.0 entirely). Causes include post-immobilization contracture, sequelae of prior Achilles repair, chronic equinus positioning, or progressive tightening associated with neurological or inflammatory conditions.

Laterality-specific codes M67.01 (right) and M67.02 (left) are the preferred choices whenever the treating clinician documents the side. CMS billing and coding articles for home health physical therapy and tendon injections list M67.01 and M67.02 explicitly — not M67.00 — as codes supporting medical necessity. This signals payer preference for laterality specificity and increases the audit risk when M67.00 is used where a side could have been documented.

Do not confuse this code with Achilles tendinitis (M65.27x), which reflects inflammation rather than structural shortening. Also exclude spontaneous tendon rupture (M66.x) and acute Achilles tendon strain (S86.01xA/D/S). M67.00 is reserved for the documented contracture or acquired shortening condition itself.

Sibling codes

Other billable codes under M67.0 (laterality / anatomic variants).

M67.02

Short Achilles tendon (acquired), left ankle

M67.01

Short Achilles tendon (acquired), right ankle

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01When should I use M67.00 instead of M67.01 or M67.02?

Only when the provider's documentation genuinely does not specify right or left ankle. If the note says 'bilateral,' code M67.01 and M67.02 together. M67.00 is not a shortcut for bilateral or unreviewed charts.

02Is M67.00 accepted by CMS for physical therapy or injection reimbursement?

CMS billing and coding articles for home health physical therapy (A57311) and tendon/ligament injections (A57079) list M67.01 and M67.02 as supporting codes — not M67.00. Using the unspecified code creates a medical necessity gap for these services.

03How does acquired Achilles tendon shortening differ from Achilles tendinitis for coding purposes?

Tendinitis (M65.27x) is an inflammatory diagnosis; short Achilles tendon (M67.0x) is a structural contracture diagnosis. They may coexist but are not synonymous — code both only when both are explicitly documented.

04Can M67.00 be used for a congenital short Achilles tendon?

No. The 'acquired' designation is part of the code definition. Congenital Achilles tendon shortening maps to a different code family. If the etiology is congenital, M67.00 is incorrect.

05What CPT procedures are commonly reported with M67.00 or its laterality-specific siblings?

Gastrocnemius recession (27687), Achilles tendon lengthening (27685), and physical therapy codes such as 97110 (therapeutic exercise) are typical procedure pairings. Injection of the tendon sheath (20550) may also apply when conservative treatment is being attempted.

06Does M67.00 require a 7th-character extension?

No. M-codes in Chapter 13 do not use 7th-character extensions. The 7th-character A/D/S convention applies to injury S-codes only. M67.00 is complete as a 5-character code.

Sources & references

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

Mira AI Scribe

Mira AI Scribe captures ankle dorsiflexion deficit measurements, the treating clinician's explicit statement of acquired (not congenital) etiology, affected side, and any prior immobilization or surgical history — all from the dictated encounter. That documentation enables coding to the laterality-specific M67.01 or M67.02, preventing a fallback to the less-specific M67.00 that CMS LCD coverage articles do not list and payers are more likely to flag.

See how Mira captures M67.00 documentation