Whether you’re a therapy billing newbie or a seasoned vet, knowing the ins and outs of modifier 59—and when it’s appropriate to bill with this “last resort” modifier—can be difficult and just plain confusing. With CMS’s recent release of new eval and re-eval CPT codes, your confusion may be intensifying. But, don’t let this weighty topic keep you up at night. Instead, look to the information below to fine-tune your billing and documentation efforts.

Proper Use of Modifier 59

As I touched on above, modifier 59 isn’t some across-the-board free pass to higher reimbursement. There are hard and fast rules about its application. Essentially, if you want to avoid a potential claims audit, modifier 59 should be the exception—not the rule. So, when can you use it? Here are the criteria for proper modifier 59 use:

You must perform services that are considered separate and distinct.

According to this WebPT Blog post, “under certain circumstances, the physician may need to indicate that a procedure or service was distinct or independent from other services performed on the same day. Modifier 59 is used to identify procedures [and/or] services that are not normally reported together, but are appropriate under the circumstances.”

You must bill for services that form edit pairs.

Rehab therapy providers can also use modifier 59—specifically, in conjunction with CCI edit pairs. So if you, the PT, bill two codes that are considered a linked pair, you’ll receive payment for only one of those codes. That is, of course, unless you determine that you performed the services separately and independently of one another—in which case you can affix modifier 59 to the claim and receive separate payment for each procedure.

You should only use this modifier when there isn’t a better option.

That said, modifier 59 shouldn’t be your go-to option for securing separate payment for linked services. Instead, as the CPT manual states, “when another already established modifier is appropriate, it should be used rather than modifier 59. Only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used.” To that end, CMS recently created a new set of modifiers—XE, XP, XS, and XU—for providers to use in place of modifier 59, when appropriate. However, therapists should hold off on using these new modifiers until further notice.

CCI Edit Pairs for the New PT and OT Evaluation Codes

Below is a chart indicating which services—denoted by the list of CPT codes in the far right column—form edit pairs with the eight new CPT codes that PTs and OTs now use for patient evals and re-evals. (If you’re looking for a full list of therapy-relevant CCI edit pairs, check out this resource.)

Providers are able to use modifier 59 if there’s a “y” next to the CPT code in the far right column. If there’s an “n” next to the code in the far right column, you should not use modifier 59 when billing that code in combination with the code in the far left column (i.e., the eval or re-eval code). If you elect to use modifier 59, you should affix the modifier to the code that appears in the far right column (not the code in the far left column).

Again, you should not use modifier 59 simply to ensure payment for both codes in an edit pair; in fact, just because you can use it doesn’t necessarily mean that you should. Your documentation must support your conclusion that you did, in fact, perform the services separately and independently of one another.

CPT Code

Description

Timed?

y = use modifier 59

n = don’t bill the code in combination with code in column 1

97161

PT evaluation:
low complexity

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97140y; 97150n; 97530n; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97164n; 97165n; 97166n; 97167n; 97168n

97162

PT evaluation: moderate complexity

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97140y; 97150n; 97530n; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97161n; 97164n; 97165n; 97166n; 97167n; 97168n

97163

PT evaluation:
high complexity

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97140y; 97150n; 97530n; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97161n; 97162n; 97164n; 97165n; 97166n; 97167n; 97168n

97164

PT re-evaluation

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97165n; 97168n

97165

OT evaluation:
low complexity

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97140y; 97150n; 97530n; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97164n; 97168n

97166

OT evaluation: moderate complexity

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97140y; 97150n; 97530n; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97164n; 97165n; 97168n

97167

OT evaluation:
high complexity

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97140y; 97150n; 97530n; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97164n; 97165n; 97166n; 97168n

97168

OT re-evaluation

No

95831n; 95832n; 95833n; 95834n; 95851n; 96105y; 96125y; 97750n; 97755n; 97762n; 99201y; 99202y; 99203y; 99204y; 99205y; 99211y; 99212y; 99213y; 99214y; 99215y; 97164n

Below is a chart indicating therapy-relevant edit pairs in which one or more of the eight new evaluative codes appear in the far right column—meaning you would affix modifier 59 to the appropriate evaluation or re-evaluation code (when all other criteria are met).

As with the first chart, providers are able to use modifier 59 if there’s a “y” next to the CPT code in the far right column. If there’s an “n” next to the code in the far right column, you should not use modifier 59 when billing that code in combination with the code in the far left column (i.e., the eval or re-eval code).

CPT Code

Description

Timed

y= use modifier 59
n= do not bill the code in combo with code in column 1

G0237

Therapeutic procedures to increase strength or endurance of respiratory muscles

Y

97161y; 97162y; 97163y; 97164y; 97165y; 97166y; 97167y; 97168y; 97750y; 97530y; 97150y; 97112y; 97110y

G0238

Therapeutic procedures to improve respiratory function, other than described by G0237

Y

97161y; 97162y; 97163y; 97164y; 97165y; 97166y; 97167y; 97168y; 97750y; 97530y; 97150y; 97112y; 97110y

G0239

Therapeutic procedures to improve respiratory function or increase strength or endurance of respiratory muscles, two or more individuals

N

97161y; 97162y; 97163y; 97164y; 97165y; 97166y; 97167y; 97168y; 97750y; 97530y; 97150y; 97112y; 97110y

96111

Developmental testing, extended

N

96125y; 97161y; 97162y; 97163y; 97164y; 97165y; 97166y; 97167y; 97168y; G0451n; G0459n;

97012

Mechanical Traction

N

97164y; 97168y; 97018y; 97140y

G0281

Electrical Stimulation – Stage 3-4 Wounds

N

97164y; 97168y; 97032y; G0283y

G0283

Electrical Stimulation – Other Than Wound Care

N

97164y; 97168y; 97032y; G0283y

97016

Vasopneumatic device

N

97164y; 97168y; 97018y; 97026y

97018

Paraffin Bath

N

97164y; 97168y; 97022y

97022

Whirlpool

N

97164y; 97168y;

97024

Infrared

N

97164y; 97168y; 97018y; 97022y

97028

Ultraviolet

N

97164y; 97168y;; 97018y; 97022y; 97026y

97032

Electrical Stimulation

Y

64550y; 97164y; 97168y;

97033

Electrical Current

Y

97164y; 97168y;

97034

Contrast Bath

Y

97164y; 97168y;

97035

Ultrasound

Y

97164y; 97168y;

97036

Hubbard Tank

Y

97164y; 97168y

97039

Physical Therapy Treatment

Y

97164y; 97168y;

97110

Therapeutic Exercises

Y

97164y; 97168y;

97112

Neuromuscular Reeducation

Y

97164y; 97168y; 97022y; 97036y

97113

Aquatic Therapy/Exercises

Y

97164y; 97168y; 97022y; 97036n; 97110y

97116

Gait Training

Y

97164y; 97168y;

97124

Massage

Y

97164y; 97168y;

97139

Physical Medicine Procedure

Y

97164y; 97168y;

97140

Manual Therapy

Y

95851y; 95852y; 97164y; 97168y; 97018y; 97124n; 97530y; 97750y; 97161y; 97162y; 97163y; 97165y; 97166y; 97167y; 97169y; 97170y; 97171y; 97172y

97150

Group Therapeutic Procedures

Y

97164y; 97168y; 97110y; 97112y; 97113y; 97116y; 97124y; 97140y; 97530y; 97532y; 97533y; 97535y; 97537y; 97542y; 97760y; 97761y; 97161n; 97162n; 97163n; 97165n; 97166n; 97167n; 97169n; 97170n; 97171n; and 97172n

97530

Therapeutic Activities

Y

95831n; 95832n; 95833n; 95834n; 95851n; 95852n; 97164y; 97168y; 97113y; 97116y; 97532y; 97533y; 97535y; 97537y; 97542y; 97750y; 97161n; 97162n; 97163n; 97165n; 97166n; 97167n; 97169n; 97170n; 97171n; and 97172n

97532

Cognitive Skills Development

Y

97164y; 97168y;

97533

Sensory Integration

Y

97164y; 97168y;

97535

Self Care Management Training

Y

97164y; 97168y;

97537

Community/Work Reintegration

Y

97164y; 97168y;

97542

Wheelchair Management Training

Y

97164y; 97168y;

97545

Work Hardening

Y

97164y; 97168y; 97140n

97597

Wound Care Selective First 20 sq centimeters

N

29105y; 29125y; 29130y; 29260y; 29345y; 29405y; 29425y; 29445y; 29515y; 29540y; 29550y; 29580y; 29581y; 29582y; 29584y; 97164y; 97022y; 97602n; 97605y; 97606y; 97610y

97598

Wound Care Selective; Each Additional 20 sq Centimeters

N

29580y; 29581y; 29582y; 97164y; 97022y; 97602n; 97605y; 97606y; 97610y

97602

Wound Care Non-Selective

N

29580y; 29581y; 97164y

97605

Negative pressure wound therapy utilizing DME (surface area less than or equal to 50 square centimeters)

N

97164y;

97606

Negative pressure wound therapy utilizing DME (surface area greater than 50 square centimeters)

N

97164y;

97608

Negative pressure wound therapy utilizing disposable, non-durable medical equipment (surface area greater than 50 square centimeters)

N

97164y;

97760

Orthotic Management & Training

Y

29105y; 29125y; 29126y; 29130y; 29131y; 29200y; 29240y; 29260y; 29280y; 29505y; 29515y; 29520y; 29530y; 29540y; 29550y; 29580y; 29581y; 29582y; 29583y; 29584y; 97164y; 97168y; 97016y; 97110y; 97112y; 97116y; 97124y; 97140y; 97662y

97761

Prosthetic Training

Y

97164y; 97168y; 97016y; 97110y; 97112y; 97116y; 97124y; 97140y; 97760y; 97762y

Two Case Examples

Phew, that’s quite the list of codes. But, what good is this chart without proper application? Here are a couple examples of how to decide whether billing with modifier 59 is appropriate.

Example 1

97161 – Physical therapy evaluation (low complexity)

95832 – Muscle testing, hand

As noted in the first chart above, 97161 and 95832 do, in fact, form an edit pair. However, regardless of whether therapists perform these procedures during separate time intervals, they cannot bill—and receive payment for—both codes, because this particular edit pair isn’t eligible for modifier 59.

Example 2

97164 – Physical therapy re-evaluation

97140 – Manual therapy

As noted in this resource, 97140 can be billed when a therapist performs manual therapy techniques (e.g., connective tissue massage, joint mobilization and manipulation, and manual traction) during a 15-minute period. A PT re-evaluation (97164), on the other hand, requires an examination that reviews the patient’s history using standardized tests and measures. The re-eval also requires a revised plan of care using “a standardized patient assessment instrument and/or measurable assessment of functional outcome.”

Now, these two codes form an edit pair, meaning that if a therapist billed them together, he or she would only receive payment for one service. However, because—as indicated in the chart above—this edit pair is eligible for modifier 59, the therapist could potentially receive separate payment as long as he or she provided the two services separately and independently of one another. To do so, the therapist would affix modifier 59 to the 97164.


What challenges have you previously run across with modifier 59? What strategies do you plan on deploying to ensure you receive the payment you deserve? Leave your thoughts in the comment section below. And for up-to-date advice on modifier 59-related denials, be sure to check out this billing FAQ.