Mri jnt of lwr extre w/o dye
CPT code 73721 covers an MRI scan of a joint in the lower body (like knee, ankle, or hip) performed without using contrast dye. This imaging test helps doctors see detailed pictures of bones, cartilage, ligaments, and other soft tissues to diagnose injuries or diseases.
RVU breakdown
Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High
Billing tips
Always append laterality modifiers (RT/LT) even though not strictly required by Medicare - many commercial payers will deny without them
Impact: Prevents 15-20% of initial denials and reduces reprocessing delays of 30-45 days
Split bill 73721 with modifier 26 and TC when radiologist and facility are separate entities to ensure both parties receive appropriate reimbursement
Impact: Professional component receives approximately $50-$65, technical component receives $135-$150 based on contract rates
Document specific joint imaged in medical record (knee vs ankle vs hip) as 73721 covers all lower extremity joints - specificity prevents denials
Impact: Reduces medical necessity denials by 25% and expedites prior authorization approval
When billing bilateral lower extremity joint MRIs on same date, append modifier 50 or bill each side separately with RT/LT modifiers depending on payer preference
Impact: Bilateral modifier typically reimburses at 150% of unilateral rate ($300.33 vs $400.44 for two separate claims)
Verify prior authorization requirements before scheduling - most commercial payers require pre-cert for non-facility MRI services
Impact: Prevents 100% payment denial; retroactive authorizations granted in less than 30% of cases
Submit radiology report with initial claim submission for commercial payers to reduce requests for medical records
Impact: Decreases payment delays by 10-15 days and reduces administrative follow-up by 40%
Common denials
Lack of medical necessity documentation - insufficient clinical information supporting need for MRI versus plain radiographs or other imaging
How to appeal: Submit clinical notes documenting failed conservative treatment, physical exam findings, and specific diagnostic question. Include relevant prior imaging reports showing progression or inadequate visualization. Reference LCD guidelines showing covered indications such as ligament tears, occult fractures, or pre-surgical planning.
Missing or incorrect laterality modifier causing claim to reject as incomplete
How to appeal: Resubmit corrected claim with appropriate RT or LT modifier within timely filing limits. Include radiology report clearly documenting which joint was imaged. Request review as corrected claim rather than appeal to expedite processing.
Prior authorization not obtained or expired at time of service
How to appeal: Request retroactive authorization with submission of clinical documentation supporting urgency or emergency nature of imaging. If denied, file appeal with peer-to-peer review between ordering physician and medical director. Success rate for retroactive auth is low (20-30%), so focus on demonstrating emergent clinical need.
Bundling denial when billed same day as other imaging or E/M service without appropriate modifiers
How to appeal: Appeal with documentation showing distinct session or separate anatomic site. Use modifier 59 or XU on rebilled claim. Provide time documentation showing services were non-overlapping. For E/M denials, submit notes proving separately identifiable evaluation beyond order for imaging.
Frequently asked questions
What is the Medicare reimbursement rate for CPT 73721 in 2025?
The 2025 Medicare national average reimbursement for CPT 73721 is $200.22 for both facility and non-facility settings. This rate is based on 6.19 total RVUs multiplied by the 2025 conversion factor of 32.3465. Actual reimbursement may vary based on geographic locality adjustments.
Does CPT 73721 require a modifier for knee MRI versus ankle MRI?
CPT 73721 covers any lower extremity joint (knee, ankle, hip, etc.) without requiring different codes for each joint. However, laterality modifiers RT (right) or LT (left) should be appended to specify which side was imaged. The specific joint should be documented in the radiology report but does not change the CPT code.
Can you bill CPT 73721 with an office visit on the same day?
Yes, but the E/M service must be separately identifiable from the decision to order the MRI. Append modifier 25 to the E/M code if significant separately identifiable evaluation and management was performed. Documentation must support that the E/M service went beyond simply ordering the imaging study.
What is the difference between CPT 73721 and 73722?
CPT 73721 is an MRI of a lower extremity joint without contrast, while CPT 73722 is the same imaging with contrast material (dye) injection. Code 73723 covers MRI both without and with contrast. The choice depends on clinical indication - contrast is typically used to evaluate infection, tumors, or enhance vascular structures.
How do you bill for bilateral knee MRIs?
For bilateral lower extremity joint MRIs, either bill 73721 twice with RT and LT modifiers, or bill once with modifier 50 (bilateral procedure), depending on payer preference. Medicare typically accepts modifier 50 and reimburses at 150% of the unilateral rate. Always verify payer-specific bilateral billing requirements.
Does CPT 73721 require prior authorization?
Medicare does not universally require prior authorization for 73721, but many Medicare Advantage and commercial plans do require pre-certification for outpatient MRI services. Requirements vary by payer and plan type. Always verify authorization requirements before scheduling to avoid payment denials.
What are the RVU values for CPT 73721 in 2025?
CPT 73721 has 2025 RVU values of: Work RVU 1.35, Practice Expense RVU 4.75 (both facility and non-facility), and Malpractice RVU 0.09, for a total of 6.19 RVUs. These values are from the CMS Physician Fee Schedule RVU25A released December 23, 2024.