Home / All Categories / DMEPOS Modifiers / Modifier BU

Modifier BU

No Beneficiary Purchase or Rental Election After 30 Days

Modifier BU identifies when a beneficiary has been informed of the purchase and rental options for eligible durable medical equipment (DME) but has not made a decision after 30 days.

On This Page

Related Modifiers

Modifier BP

Purchase Election

Modifier BR

Rental Election

Modifier RR

Rental Equipment

When to Use

When NOT to Use

BU vs. BP & BR

Billing Example

Election Rules

Documentation

Billing Errors

FAQs

What Is Modifier BU?

Modifier BU is a HCPCS Level II modifier used when a beneficiary has been informed of the available purchase and rental options for eligible durable medical equipment but has not elected either option after 30 days.

Its official descriptor is “The beneficiary has been informed of the purchase and rental options and after 30 days has not informed the supplier of his/her decision.”

Modifier BU is associated with certain DME items subject to beneficiary purchase and rental election requirements, particularly equipment classified as inexpensive or routinely purchased under Medicare payment rules.

Unlike Modifier BP or BR, which identify an affirmative beneficiary election, BU identifies the absence of a decision after the applicable notification period.

Important: Modifier BU does not mean that the beneficiary has refused equipment or that the supplier can automatically bill for a purchase. Under applicable Medicare election rules, the supplier generally continues billing on a rental basis when the beneficiary has not made an election.

Quick Reference

Modifier: BU

Type: Beneficiary Election

Category: DMEPOS

Meaning: No Election

Billing: Rental Basis

Timeframe: 30 Days

When to Use Modifier BU

No Beneficiary Decision

Report BU when the beneficiary has not selected either the purchase or rental option after the applicable 30-day notification period.

Purchase and Rental Options Explained

The supplier must have informed the beneficiary of the available purchase and rental options before the election period begins.

Eligible Equipment Category

Use BU only for equipment subject to the applicable beneficiary election requirements.

Documented Notification Date

Maintain records establishing when the beneficiary was informed of the options and when the 30-day period expired.

Payer Requires BU

Append BU when the payer's billing instructions require it to identify an unresolved beneficiary election.

Important: BU should reflect a documented absence of an election after 30 days, not an assumption that the beneficiary prefers rental.

When NOT to Use Modifier BU

Beneficiary Elects Purchase

Do not report BU when the beneficiary affirmatively chooses to purchase eligible equipment. Modifier BP may apply.

Beneficiary Elects Rental

Do not use BU when the beneficiary chooses to rent. Modifier BR may be appropriate.

30-Day Period Has Not Expired

Do not report BU before the applicable election period has elapsed.

Notification Not Provided

Do not use BU when the beneficiary was never informed of the required purchase and rental options.

Standard Rental Equipment

Do not automatically append BU to DME items that are not subject to beneficiary election requirements.

Important: BU is not a general-purpose modifier for missing paperwork, delayed authorization, or an incomplete equipment order.

Modifier BU vs. BP and BR

These three modifiers identify different outcomes of the beneficiary purchase and rental election process.

Modifier BU – No Election After 30 Days

The beneficiary has been informed of the options but has not communicated a decision after the applicable 30-day period.

Modifier BP – Purchase Election

The beneficiary has been informed of the available options and elects to purchase the equipment.

Modifier BR – Rental Election

The beneficiary has been informed of the available options and elects to rent the equipment.

Key Difference: BP and BR represent affirmative beneficiary decisions. BU identifies an unresolved election after the required notification period.

BU vs. RR

Modifier RR identifies equipment furnished on a rental basis. Modifier BU identifies the beneficiary's election status. These modifiers serve different purposes and should be reported according to the payer's instructions.

Billing Example

A Medicare beneficiary requires a standard manual wheelchair for use at home.

The supplier confirms that the equipment is subject to the applicable purchase and rental election requirements and informs the beneficiary of both options.

After 30 days, the beneficiary has not communicated a decision. The supplier documents the notification and lack of election and follows the applicable rental billing requirements.

Example – No Election After 30 Days:

K0001-BU

Claim Details:

HCPCS Code: K0001 – Standard Wheelchair

Modifier BU: No Election After 30 Days

Equipment: Manual Wheelchair

Billing Arrangement: Rental Basis

Documentation: Beneficiary Notification Record

Medical Necessity: Required

Important: This example illustrates the modifier's purpose. The supplier must verify that the equipment's payment category permits BU and follow current payer requirements for rental billing, modifier combinations, and claim submission. Not every manual wheelchair claim requires BU.

Medicare 30-Day Beneficiary Election Rule

The 30-day election period is the defining feature of Modifier BU. Correct reporting depends on when the beneficiary was notified and whether a decision was communicated.

Beginning the Election Period

The supplier must inform the beneficiary of the applicable purchase and rental options. Documentation should identify the notification date.

No Decision After 30 Days

When the beneficiary has not communicated a decision after 30 days, BU may apply to the eligible equipment claim under the payer's election rules.

Rental Billing

For Medicare equipment subject to this election framework, an unresolved election generally results in continued rental billing rather than an automatic purchase.

Later Beneficiary Election

If the beneficiary subsequently communicates a purchase or rental decision, the supplier must follow the applicable rules for documenting and billing the election. Previous claims should not be changed without confirming the payer's requirements.

Equipment Category Restrictions

The BP, BR, and BU election framework does not apply universally to capped rental equipment, oxygen equipment, or every other DME category.

Important Billing Rule: The expiration of the 30-day period does not independently establish coverage, medical necessity, or eligibility for a purchase payment.

Documentation Requirements

Modifier BU claims require documentation showing that the beneficiary received the required purchase and rental information and did not communicate an election within the applicable period.

Equipment Order

Maintain a valid order identifying the prescribed equipment and supporting the applicable coverage requirements.

Beneficiary Notification

Document when and how the purchase and rental options were explained.

Election Timeline

Record the notification date and establish that the required 30-day period elapsed.

No Election Record

Maintain documentation showing that no purchase or rental election was received within the applicable period.

Rental and Delivery Records

Retain the applicable rental agreement, proof of delivery, and supporting claim records.

Documentation Checklist

Valid equipment order retained
Medical necessity supported
Purchase and rental options explained
Notification date documented
30-day period verified
No beneficiary election recorded
Equipment eligibility and rental records confirmed

Important: A missing election form alone does not establish that BU is appropriate. The supplier must verify that the required notification occurred and that the election period expired.

Common Billing Errors and Denials

Modifier BU claims may be denied when the beneficiary notification, election timeline, equipment eligibility, or supporting documentation does not satisfy payer requirements.

Modifier BU Reported Too Early

Submitting BU before the applicable 30-day election period has elapsed.

Missing Beneficiary Notification

Failing to document that the beneficiary received the required purchase and rental information.

Incorrect Election Status

Using BU when the beneficiary already selected purchase or rental.

Ineligible Equipment Category

Appending BU to equipment that does not qualify for the applicable beneficiary election arrangement.

Incorrect Rental Billing

Submitting claims that do not comply with the equipment's payment category, rental limits, or payer-specific modifier requirements.

Incomplete Documentation

Failing to maintain records establishing the notification date, lack of election, or medical necessity.

Understanding Beneficiary Election Denials

When a Modifier BU claim is denied, review the Claim Adjustment Reason Code (CARC) and associated Remittance Advice Remark Codes (RARCs).

For example, CO-16 indicates that a claim or service lacks information or contains submission errors needed for adjudication. The accompanying remark codes may identify the specific information requiring correction.

For explanations of claim adjustment codes and guidance on resolving medical billing denials, visit DenialCodeLookup.com.

Important: Verify the beneficiary notification timeline, election records, equipment payment category, and payer instructions before correcting or appealing the claim.

Frequently Asked Questions

Does Modifier BU mean the beneficiary has refused to purchase or rent the equipment?

No. BU indicates that the beneficiary has not communicated a decision after the applicable 30-day period. It does not establish that the beneficiary refused the equipment or declined coverage.

Can Modifier BU be used if the beneficiary initially chose rental but later stopped responding?

Generally, no. If the beneficiary already made a valid rental election, the appropriate election status is BR rather than BU. A later failure to respond does not automatically invalidate the original election.