What is a modifier 50 used for?

• Modifier 50 applies to bilateral procedures performed on both sides of the body during the same operative session.
• When a procedure is identified by the terminology as bilateral or unilateral, the 50 modifiers are not reported.
• If a procedure is authorized for the 150 percent payment adjustment for bilateral procedures (payment policy indicator 1), the procedure should be reported on a single line item with the 50 modifiers and one service unit.
• Whenever the 50 modifiers are appended, the appropriate number of service units is one.
• Modifiers LT (left side) and RT (right side) are not to be reported when the 50 modifier applies.
• Claims with the LT and RT modifiers will be returned to the provider (RTP) when modifier 50 applies

Effective for claims received on and after August 16, 2019, services will be rejected as un-processable when the procedure code reported is inconsistent with the modifier used. The modifier 50 is defined as a bilateral procedure performed on both sides of the body.

Appropriate Use

• Report one line with modifier 50 using one unit of service
• If more than one bilateral procedure was performed the number of units should be adjusted to reflect the number of bilateral procedures that are performed.

Note: It is recommended that anatomical modifier be included in addition to the 50 modifiers to show the additional services are not duplicates.

Example:

Procedure code 19303 (Mastectomy, simple, complete) is performed bilaterally

Correct Coding

Incorrect Coding

Inappropriate Use

• Inappropriate to apply to a “bilateral description” code.
• Do not append to procedures for midline organs such as the bladder, uterus, esophagus, or nasal septum.
• Inappropriate to report when performed on different areas of the same side of the body.
• It cannot be appended when bilateral indicators are 0, 2, or 9.

Example:

The terminology for procedure code 27158 (osteotomy, pelvis, bilateral) indicates the procedure is performed bilaterally. Therefore, it’s not appropriate to report with this procedure code.

Bilateral Surgery Indicators

• “0″ indicates a unilateral code; not billable.
• “1” indicates It can be appropriate.
• “2” indicates a bilateral code; It is not billable.
• “3” indicates primary radiology codes; It is billable.
• “9” indicates that the concept does not apply. (office visit)

Medically Unlikely Edits (MUE) and Bilateral Procedures

When reporting bilateral surgical procedures that have an MUE Adjudication Indicator (MAI) of “2” or “3”, the bill with modifier 50 and one unit of service.

Ambulatory Surgical Centers (ASCs) and Modifier

Bilateral surgical procedures furnished by certified ASCs may be covered under Part B. While the use of the 50 modifiers is not prohibited, according to Medicare billing instructions, the modifier is not recognized for payment purposes and if used, may result in incorrect payment to ASCs.

Bilateral procedures should be reported as a single unit on two separate lines or a single unit with “2” in the unit field on one line, in order for both procedures to be paid correctly. The multiple procedure reduction of 50 percent will apply to all bilateral procedures subject to multiple procedures discounting. Multiple surgery pricing applies to bilateral services (modifier 50) performed on the same day with other procedures.

Surgical modifiers 50 and 52 and modifier 59 are crucial to telling the story of a claim by identifying procedures that have been altered, without changing the core meaning of the code(s) submitted. Let’s focus on proper application and instructive resources for these three modifiers.

Surgical modifier 50 Bilateral procedure describes procedures/services that occur on identical, opposing structures (e.g., eyes, shoulder joints, breasts). Follow these rules for appropriate use:

• Do use modifier 50 on bilateral body organs, such as the kidneys, ureters, and hands.
• Do not append modifier 50 to procedures on the skin because the skin is one organ.
• Do use modifier 50 when the code description does not already state the procedure is bilateral.
• Do not use modifier 50 when “one or both” is in the code description.

When deciding whether to use modifier 50, it’s sometimes difficult to determine if the procedure is considered bilateral. An easy way to tell is to consult the Medicare Physician Fee Schedule (MPFS).  A table, similar to the condensed version shown in Table A, identifies which procedures Medicare identifies as bilateral. Remember: Commercial carriers may follow their own guidelines.

Example A in Table A indicates that code 68840 Probing of lacrimal canaliculi, with or without irrigation has a bilateral surgery indicator of 1. This denotes that the procedure is unilateral, as described in CPT®, and can be appropriately billed as a bilateral procedure with modifier 50 appended. Medicare will pay this procedure at 150 percent of the allowed amount, subject to the patient’s deductible and coinsurance. Be sure to increase the billed amount when the claim is submitted; Medicare will not increase this amount on its own. As an example, if the allowed amount for 68840 is $100, the coder should increase the billed amount to $150 on the claim form.

Example B indicates code 60220 Total thyroid lobectomy, unilateral; with or without isthmusectomy has a bilateral surgery indicator of 0. This procedure code cannot be billed as a bilateral procedure because the thyroid is not a bilateral body part. When the indicator 0 is designated, it means that the physiology, anatomy, or the code descriptor specifically states the procedure is unilateral or there is an existing code for the bilateral procedure. Never append modifier 50 to these procedures.

In Example C, code 58210 Radical abdominal hysterectomy, with bilateral total pelvic lymphadenectomy and para-aortic lymph node sampling (biopsy), with or without removal of tube(s), with or without removal of ovary(s) has a bilateral indicator of 2. These procedures are considered “inherently bilateral,” which means the code descriptor or procedure specifically includes bilateral body parts. In this example, the code descriptor includes bilateral lymph nodes and, dependent on the extent of the procedure, the fallopian tubes and ovaries. The allowed fee schedule for inherently bilateral procedures already includes payment for a bilateral service, so modifier 50 should not be used and the billed amount should not be increased.

A bilateral indicator of 3 (not shown here because it does not apply to surgery procedures) is considered “independently bilateral,” and usually applies to radiology procedures and diagnostic tests. These codes are considered bilateral if modifier 50 is present; and full payment should be made for each procedure. One such code is 73080 Radiologic examination, elbow; complete, minimum of 3 views. For example, if this procedure is performed on both the left and right elbows, and one procedure has an allowed amount of $100, the total allowed amount for 73080-50 would be $200.

Different carriers require different reporting of bilateral procedures and offer different reimbursement methodologies. For examples of common carrier preferences, see Table B.

Check your carriers’ online medical policy base or review your physicians’ contracts for instructions on applying modifier 50 properly on claims forms.

What is Modifier 51?

Surgical modifier 51 Multiple procedures indicates that the same provider performed multiple procedures — other than E/M services — at the same session. You should list the most resource-intense (highest paying) procedure first, and append modifier 51 to the second and subsequent procedures.
Use modifier 51 to indicate:

• Same procedure, different sites
• Multiple operation(s), same operative session
• Procedure performed multiple times

Most payers apply a “multiple procedure discount” with modifier 51. This refers to the practice of reducing the reimbursement for subsequent procedures because of shared resources when two or more procedures are performed together. CPT® Appendix E lists codes that are exempt from modifier 51.

The following is an example of multiple operations in the same operative session:
Scenario: The patient presents for removal of a 0.5 cm (as measured by CPT® guidelines) malignant skin lesion on the trunk. A layered closure of the resulting wound is performed in the same operative session. The appropriate coding is:
12031 Repair, intermediate, wounds of scalp, axillae, trunk and/or extremities (excluding hands and feet); 2.5 cm or less [typically 100 percent allowed reimbursement*]
11600-51 Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 0.5 cm or less [typically reduced reimbursement*]

*Dependent on carrier policy. You should also note that a few carriers may automatically order the procedure codes based on that carrier’s fee schedules.

What is Modifier 59?

CPT Modifier 59 Distinct procedural service is used to indicate:

• Different session or encounter
• Different procedure
• Different site
• Separate incision, excision, lesion, injury, or body part

Modifier 59 is frequently appended to those codes defined as “separate procedures” in CPT®. Designated separate procedures commonly are carried out as an integral component of a more extensive procedure. Only when a procedure or service designated as a separate procedure is carried out independently, and is considered to be unrelated or distinct, may it be reported separately.

For example, 29870 Arthroscopy, knee, diagnostic, with or without synovial biopsy (separate procedure) is a designated separate procedure. If this procedure is:

• Performed alone (e.g., on the left knee): Report 29870-LT.
• Performed as an integral part of another procedure (e.g., a diagnostic arthroscopy and surgical arthroscopy on the right knee): Do not bill the separate procedure. Code only the surgical arthroscopy 29866-RT Arthroscopy, knee, surgical; osteochondral autograft(s) (eg, mosaicplasty) (includes harvesting of the autograft[s]).
• Performed as a distinct procedure (e.g., a diagnostic arthroscopy on the left knee and a surgical arthroscopy on right knee in same surgical session): Report 29866-RT and 29870-59-LT. As with modifier 51, list first the more resource-intense procedure (in this case, the surgical approach).

In another example, the patient presents for an excision of a right arm skin lesion, which is benign, and a biopsy of a skin lesion on the left arm. These codes usually are not reported together because CPT® instructs, “the obtaining of tissue for pathology during the course of [surgical procedures in the integumentary system] is … not considered a separate biopsy procedure and is not separately reported.” In this case, however, the procedures are performed on two distinct body sites, and we are further instructed, “The use of a biopsy procedure code (e.g., 11100, 11101) indicates that the procedure … was unrelated or distinct from other procedures/services provided at that time.”
The appropriate coding is:

• 11403 Excision, benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms or legs; excised diameter 2.1 to 3.0 cm for the right arm skin lesion excision, with ICD-9-CM code 216.6 Benign neoplasm of skin; skin of upper limb, including shoulder
• 11100-59 Biopsy of skin, subcutaneous tissue and/or mucous membrane (including simple closure), unless otherwise listed; single lesion for the left arm skin lesion biopsy, with ICD-9-CM code 238.2 Neoplasm of uncertain behavior of other and unspecified sites and tissues; skin

Once again, you should list first the more resource-intense procedure (the benign lesion excision). Follow that with the biopsy, appending modifier 59 and linking it with the “uncertain behavior of neoplasm” diagnosis code.

The Difference Between Modifiers 51 and 59

According to CPT®, when multiple procedures are performed at the same session by the same provider, you may identify the additional procedure(s) or service(s) by appending modifier 51. CPT®, however, also instructs us to use modifier 59 to identify two procedures or services that are not usually submitted together, but are appropriate under the circumstances. CPT® further instructs us not to use modifier 59 if another already established modifier is appropriate. This is how modifier 59 earned its nickname, “The modifier of last resort.”

When choosing between modifiers 51 and 59, payer policy may be the determining factor. Some payers, including Medicare contractors, do not acknowledge modifier 51. And, though we should not code solely based on reimbursement, keep in mind that modifier 51 may trigger the multiple payment reduction. On the other hand, modifier 59 may trigger a front-end edit, and the payer may require documentation, which will inevitably delay claim reimbursement.

A good reference are the National Correct Coding Initiative (NCCI) edits, which provide directions on when to appropriately “unbundle” procedure codes, as illustrated in Table C. NCCI edits are valid for Medicare only, but other payers are permitted to follow these guidelines. You can find NCCI resources on the CMS website).

NCCI edits are referred to as Column 1 and Column 2 codes: Column 1 is the reimbursable code; and column 2 is not payable unless a modifier is permitted and submitted. An edit of 1 in the first pair of codes indicates that the column 2 code is a component of the column 1 code, but can, at times, be billed separately with modifier 59 appended. The first pair of codes in Table C relate to the example previously reviewed. In this example, the procedures were performed on different sites, so the use of modifier 59 is correct.

The second set of codes, 11100 and 99149 Moderate sedation services (other than those services described by codes 00100-01999), provided by a physician other than the health care professional performing the diagnostic or therapeutic service that the sedation supports; age 5 years or older, first 30 minutes intra-service time are listed with a 0, which indicates that they cannot be billed together using any modifier.

The last code pair, +11201 Removal of skin tags, multiple fibrocutaneous tags, any area; each additional 10 lesions, or part thereof (List separately in addition to code for primary procedure) and the column 2 code of 10060 Incision and drainage of abscess (eg, carbuncle, suppurative hidradenitis, cutaneous or subcutaneous abscess, cyst, furuncle, or paronychia); simple or single are assigned a 9 indicator. This means that an NCCI edit does not apply to this code pair. If the procedures were performed in the same operative session, use modifier 51 for multiple procedures on the column 2 code (10060), based on carrier policy.

Get Paid Using Modifiers 50, 51, 59 was last modified: September 6th, 2022 by Nancy Clark