PR-51: Pre-Existing Condition Exclusion

What Does PR-51 Mean?

PR 51 shifts financial responsibility to the patient because their insurance plan excludes coverage for services related to their pre-existing condition. This is most common with grandfathered plans, short-term insurance, or plans that legally permit pre-existing condition exclusions. The patient may not have been aware of this limitation at enrollment. The provider can bill the patient for the full amount, but should verify the exclusion is correctly applied before doing so.

CARC 51 appears on a remittance when the payer determines that the billed service is connected to a pre-existing condition that is excluded or limited under the patient's insurance plan. This denial code dates back to the era before the Affordable Care Act (ACA) made pre-existing condition exclusions illegal for ACA-compliant individual and group health plans. However, CARC 51 still applies to grandfathered plans, short-term health insurance, certain employer-sponsored plans that predate ACA requirements, and specific scenarios where pre-existing condition limitations remain legally permissible.

The practical challenge with CARC 51 is that the payer's system often triggers this denial based on the ICD-10 diagnosis code submitted, regardless of whether the current episode of care is truly related to the pre-existing condition. A patient with a history of diabetes may present with an acute condition that happens to share a similar diagnostic category, and the automated edit flags it as pre-existing. This means the denial may be incorrect and can often be overturned with proper documentation differentiating the current treatment from the pre-existing condition.

The group code assignment is important. CO 51 places the financial burden on the provider, who should look for coding or documentation corrections that could resolve the issue. PR 51 shifts the cost to the patient, which requires transparent communication about their coverage limitations and assistance with payment arrangements.

Common Causes

How to Resolve

Determine whether the service is genuinely related to a pre-existing condition or if the denial is based on an incorrect diagnostic association, then appeal or correct the claim accordingly.

1. Verify the exclusion applies Confirm with the payer that the patient's plan has a legitimate pre-existing condition exclusion and that it applies to the specific service billed. Check whether any waiting period has elapsed that would restore coverage.
2. Communicate with the patient Explain the denial clearly to the patient, including the pre-existing condition exclusion in their plan. Help them understand their appeal rights at the member level.
3. Arrange payment Set up a payment plan if the patient balance is significant. Assist with a member-level appeal if there is reason to believe the exclusion was incorrectly applied.

How to Prevent PR-51

• Screen for pre-existing condition exclusions during patient registration and eligibility verification.
• Provide cost estimates to patients whose plans have pre-existing condition limitations before rendering services.
• Educate patients about their plan's exclusions and encourage them to review their coverage during open enrollment.

General Prevention

• Inform patients during registration if their plan has pre-existing condition exclusions.
• Provide cost estimates before rendering services when pre-existing condition exclusions apply.
• Help patients understand their coverage limitations and explore alternative plan options during open enrollment.

Also Filed As

The same CARC 51 may appear with different Group Codes:

Related Denial Codes