73721 CPT Code

Do you bill for leg MRIs every day? Are you confused about CPT 73721? This code is very common in orthopedic practices. About 8 million leg MRIs are done yearly in the US. Medicare pays roughly $300-600 for this code. Proper coding prevents denials worth thousands of dollars.

CPT 73721 is for leg MRI without contrast. This includes imaging of lower extremity joints. The code covers both pro and tech parts. Over 50% of orthopedic practices use this daily. Insurance companies audit MRI claims very closely. Wrong docs cause 45% of MRI claim denials.

This guide explains CPT 73721 in simple terms. We show you proper coding and billing rules. You will learn that doc needs, too. Facts and data help you bill right. Tables make info easy to understand quickly. Follow these guidelines to get paid faster.

CPT 73721 Code Description

CPT 73721 is for MRI of the lower leg without contrast. This code includes complete imaging of leg structures. Knee, ankle, or other leg joints covered.

What CPT 73721 Includes

Component	What It Covers	Doc Needed
Lower leg imaging	Knee to ankle area	Body part specified
Multiple sequences	T1, T2, STIR views	All sequences listed
Multiple planes	Axial, sagittal, coronal	All planes documented
Joint evaluation	Bones, ligaments, tendons	Structures assessed

Code Comparison

CPT Code	Body Part	Contrast	Joints Included	When to Use
73718	Lower leg	No	Single joint	One joint only
73719	Lower leg	Yes	Single joint	Needs contrast
73720	Lower leg	No + Yes	Single joint	With and without
73721	Lower leg	No	Any joint	Most common
73722	Lower leg	Yes	Any joint	Contrast needed
73723	Lower leg	No + Yes	Any joint	Complete study

Body Parts Covered

Joint/Area	ICD-10 Code	Common Conditions	Approval Rate
Knee	S83.x	Meniscus tear, ACL tear	92%
Ankle	S93.x	Ligament tear, fracture	88%
Lower leg	S86.x	Muscle tear, strain	85%
Tibia/Fibula	S82.x	Stress fracture, bone injury	90%
Calf	M79.3	Deep tissue injury	82%

Billing Requirements for 73721

Proper billing ensures you get paid right. Doc must support the code billed always. Missing elements cause automatic claim denials.

Documentation Requirements

Required Element	Specific Details	Common Errors
Patient Info	Name, DOB, MRN	Missing medical record number
Medical Need	Reason for MRI	Vague or missing reasons
Body Part	Specific joint/area	Left vs right not specified
Sequences	All imaging sequences	Missing sequence list
Interpretation	Findings report	Missing radiologist signature
Side	Left or right leg	Laterality not documented

Medical Necessity Table

Common Indication	ICD-10 Code	Approval Rate	Auth Needed
Knee pain	M25.561/M25.562	95%	Often
Ankle pain	M25.571/M25.572	92%	Often
Suspected meniscus tear	S83.2	98%	Usually
ACL injury	S83.5	97%	Usually
Stress fracture	M84.3	90%	Sometimes
Chronic leg pain	M79.669	85%	Often

Imaging Sequences Required

Sequence Type	Purpose	Required	Common Use
T1-weighted	Anatomy detail	Yes	All studies
T2-weighted	Fluid detection	Yes	All studies
STIR	Fat suppression	Yes	Inflammation check
Proton density	Cartilage detail	Often	Joint studies
Gradient echo	Bone detail	Sometimes	Fracture check

Payment Rates for 73721

Medicare and insurance companies pay different rates. Location always affects payment amounts received. Understanding rates helps with money planning.

Medicare Payment by Location

Location Type	Pro Part	Tech Part	Total Payment
Hospital	$60-90	$240-350	$300-440
Imaging Center	$70-110	$280-420	$350-530
Office	$80-120	$320-480	$400-600
Rural	$65-95	$250-380	$315-475
Urban	$85-125	$340-520	$425-645

Commercial Insurance Rates

Private insurance pays 120-220% of Medicare rates. Some plans pay as low as 100%. Contract rates vary by individual insurance company. Prior auth almost always needed for MRI. Verify benefits before doing the study, always.

Modifiers for CPT 73721

Modifier	Purpose	When to Use	Payment Impact
26	Pro part only	Interpretation only	Reduce 70-80%
TC	Tech part only	Equipment only	Reduce 20-30%
76	Repeat same doc	Medical need repeat	Full if justified
77	Repeat different doc	New doc repeat	Full if justified
RT	Right side	Right leg imaged	No change
LT	Left side	Left leg imaged	No change
59	Separate service	Distinct procedure	Full for both

Prior Authorization Requirements

Almost all insurance plans need prior authorization for an MRI. Getting authorization prevents claim denials and payment delays.

Insurance Plan	Auth Needed	Turnaround Time	Valid Period	Denial Rate Without
Medicare Original	No	N/A	N/A	N/A
Medicare Advantage	Yes	3-7 days	30-60 days	85%
Commercial PPO	Always	2-10 days	60-90 days	90%
Commercial HMO	Always	1-5 days	30 days	95%
Medicaid	Yes	5-15 days	30-90 days	88%
Workers Comp	Always	1-3 days	Per case	92%

Conclusion

CPT 73721 is for lower leg MRI without contrast. A proper doc ensures you get paid right. Medical needs must always be clearly stated. Payment rates vary by location and insurance. Avoid common coding and doc errors completely. Use right modifiers, especially laterality ones. Prior authorization prevents claim denials in most cases. Follow quality standards for accurate diagnostic results.

FAQs

What does CPT 73721 include?

Lower leg MRI without contrast material was used. This includes knee, ankle, or other leg joints. Multiple imaging sequences in different planes are included.

How much does Medicare pay for 73721?

Medicare pays about $300-600, depending on the location setting. Hospital rates are lower than imaging center rates. The pro part is about $60-120, and the tech part is $240-480.

Do I need prior auth for 73721?

Almost all insurance plans require prior authorization first. Medicare Advantage always needs authorization before service. All commercial plans need authorization too, always.

What modifier is used for the right leg?

Modifier RT indicates the right leg was imaged. This laterality modifier is required for payment always. Left leg uses the LT modifier instead of the RT. A missing laterality modifier often causes claim denial.

How often can 73721 be billed?

Frequency depends on medical need and insurance policy. Most plans allow one MRI per year routinely. More frequent if the condition changes or worsens significantly.

What doc is required for 73721?

Complete imaging report with all sequences listed. Specific body part and laterality must be clear. All anatomical structures must be assessed and documented.