Radiologic supervision and interpretation of MRI used to guide a needle into position for a biopsy, aspiration, injection, or localization.
- Medicare
- $426.86
- Work RVU
- 1.46
- Global, days
- Region
- Multi-region
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 3 cited references ↓
- Primary procedure performed under MRI guidance, coded separately
- Reason CT, fluoroscopy, or ultrasound could not visualize the target
- Target location and lesion characteristics on MRI
- Confirmation of final needle position on MRI images
- Physician interpretation of guidance images
- Ordering provider's clinical question tied to the lesion
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 3 cited references ↓
Think of 77021 as the MRI version of 77012. It is uncommon in orthopedics because it needs an MRI-compatible suite and needles, and most bone and soft tissue targets can be reached with CT, fluoroscopy, or ultrasound. When it does appear on an ortho patient's claims, it is usually for a soft tissue or marrow lesion that only shows on MRI, sampled by interventional radiology.
The ortho practice's role is usually ordering, not billing. Your note should say why MRI was the only modality that could see the target. Payers question MRI guidance hard because it costs far more than CT guidance for what looks like the same work on paper.
Like the other guidance codes, 77021 is a supervision and interpretation code that pairs with a separately reported procedure, such as a soft tissue or bone biopsy. If the procedure code's descriptor already includes imaging guidance, 77021 does not go on top. The radiologist reports modifier 26 in a facility setting.
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 (1.46) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (12.78) adds practice overhead and malpractice, and is what drives the Medicare payment below.
| Work RVU | 1.46 |
| Practice expense RVU | 11.24 |
| Malpractice RVU | 0.08 |
| Total RVU | 12.78 |
| Medicare national rate | $426.86 |
| Global period | 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 | $426.86 |
Common denial reasons
The recurring reasons claims for CPT 77021 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- No documented reason MRI was needed over a lower-cost modality
- Billed with a procedure that already includes imaging guidance
- Missing primary procedure on the claim
- Prior authorization not obtained for MRI services
- Global billed in a facility without modifier 26
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01When is 77021 used instead of 77012?
02Does 77021 need prior authorization?
03Can 77021 be billed alone?
Sources & references
Editorial content was developed using the following public sources.
Mira Scribe
Mira Scribe documents the ordering rationale in the referral visit, including why the lesion is only visible on MRI, which is the question payers ask first.
See how Mira captures CPT 77021 documentation