Surgical procedure in which the muscles attached to the hyoid bone are cut and the bone is repositioned and anchored to an adjacent structure to open the upper airway.

Verified May 8, 2026 · 5 sources ↓

Medicare: $862.41
Work RVU: 14.88
Global, days: 90
Region: Other

Drawn from CMSProvidencehealthplanAAPCMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Preoperative sleep study (polysomnography) with AHI documented, meeting payer threshold
Documentation of CPAP trial, duration, and documented failure or intolerance
Operative note specifying myotomy technique, suspension method, and fixation target (e.g., mandible or thyroid cartilage)
Indications clearly tied to obstructive sleep apnea or documented airway pathology — not cosmetic
Surgeon attestation that all components of the procedure (both myotomy and suspension) were performed
BMI and relevant comorbidities documented in the H&P for medical necessity support

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 24 Unrelated E/M during global 25 Significant separate E/M 58 Staged or related 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 21685 describes hyoid myotomy and suspension — a procedure most commonly performed as part of a multilevel surgical protocol for obstructive sleep apnea (OSA). The surgeon incises the musculature anchoring the hyoid bone in the neck, then suspends the freed hyoid anteriorly or superiorly, typically fixing it to the mandible or thyroid cartilage. The goal is to enlarge the retrolingual and hypopharyngeal airway. It appears in sleep disorder surgery policies alongside codes like 21199 (genioglossus advancement) and is frequently staged or combined with other upper airway procedures.

The 90-day global period means all routine post-op care through day 90 is bundled. Unrelated E/M visits during that window require modifier 24. If the procedure is done the same day as a significant, separately identifiable E/M, append modifier 25 to that E/M. Prior authorization is common — many payers (and Medicare MACs) require documented CPAP failure, AHI thresholds, BMI criteria, and sleep study data before approving this code.

This code sits under Repair, Revision, and/or Reconstruction Procedures on the Neck (Soft Tissues) and Thorax in the CPT surgery section. It is predominantly billed by oral and maxillofacial surgeons. The site of service matters: HOPD and ASC facility payments differ significantly — confirm your setting before submitting.

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 (14.88) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (25.82) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	14.88
Practice expense RVU	8.72
Malpractice RVU	2.22
Total RVU	25.82
Medicare national rate	$862.41
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	$862.41
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,039.11

Common denial reasons

The recurring reasons claims for CPT 21685 get rejected.

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

Missing or insufficient prior authorization — payers routinely require pre-auth for this code
CPAP failure not documented or deemed inadequate by payer criteria
AHI or severity threshold not met per payer's sleep surgery coverage policy
Operative note lacks specifics on suspension technique, triggering a 'not medically necessary' or 'documentation insufficient' denial
Bundling conflict when billed same-day with other upper airway or craniofacial codes without appropriate modifiers

Frequently asked questions

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

01Does CPT 21685 require prior authorization with Medicare?

Medicare MACs vary, but most treat hyoid suspension as a covered surgical procedure for OSA when medical necessity criteria are met — including documented CPAP failure and qualifying AHI. Check your specific MAC's LCD for sleep disorder surgery; prior auth requirements differ by jurisdiction.

02Can 21685 be billed with genioglossus advancement (CPT 21199) on the same day?

Yes, if both procedures are performed in the same operative session, report both codes. Append modifier 51 to the lower-valued code. Confirm NCCI PTP edits for this pairing before submitting, and ensure the operative note documents each procedure distinctly.

03What ICD-10 codes support medical necessity for 21685?

G47.33 (obstructive sleep apnea, adult) is the primary diagnosis. Some payers also accept G47.30 (sleep apnea, unspecified) but prefer specificity. Document severity (mild/moderate/severe) in the record to align with payer AHI thresholds.

04What is the global period for 21685, and what's included?

21685 carries a 90-day global period. That bundles the day-before pre-op visit, the procedure itself, and all routine post-op care through day 90. Bill modifier 24 for unrelated E/M visits in that window, and modifier 79 for unrelated surgical procedures.

05Is hyoid suspension ever considered cosmetic or non-covered?

When performed solely for anatomical repositioning without a documented functional airway indication, payers can deny it as cosmetic. Tie every claim to an OSA or documented airway obstruction diagnosis with supporting sleep study data. Absence of medical necessity documentation is the most common non-coverage trigger.

06Should modifier 22 be appended if the anatomy was unusually difficult?

Yes — if calcification of the hyoid, prior neck surgery, or other factors substantially increased operative time and complexity, modifier 22 is appropriate. Attach a cover letter summarizing the added work; payers will request the operative note and may require manual review before approving the upcharge.

Sources & references

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

Mira Scribe

Mira's AI scribe captures the hyoid myotomy technique, the suspension target structure (mandible vs. thyroid cartilage), fixation method, and intraoperative confirmation that both the myotomy and suspension components were fully completed. That documentation directly satisfies the CMS requirement that all services described by the code were performed — preventing 'incomplete procedure' denials and supporting medical necessity review.

See how Mira captures CPT 21685 documentation