A practical guide to completing Box 20: Outside Lab and Charges accurately and consistently.

From our workflow: Outside Lab and Charges may be a small entry, but it affects the rest of the claim. We compare it with the source record and then confirm that the surrounding fields tell the same story.

Indicate whether purchased diagnostic services or outside-lab charges apply.

The payer does not read Outside Lab and Charges in isolation. We compare it with the surrounding claim data before deciding the entry is ready.

General rule: Payer-specific instructions, contracts, program manuals, and current coding guidance can add to or override general form guidance. Verify requirements before submission.

Why this deserves a careful check

An entry for Outside Lab and Charges may be the right length and still be the wrong value. The surrounding coverage, provider, and service information has to support it.

If Outside Lab and Charges fails an edit, verify the source and the payer rule before changing it. A guessed value can move the problem from rejection to denial.

How to enter it consistently

  1. Identify the person, organization, date, code, or identifier the field is asking for.
  2. Locate the source document: insurance card, eligibility response, clinical note, authorization, provider enrollment record, fee schedule, or payer remittance.
  3. Enter the value using the form’s structure and the payer’s required format.
  4. Compare it with related fields and service lines for consistency.
  5. Save evidence of the source and the final submitted claim.

Mistakes worth catching early

  • Marking yes for every referred test.
  • Omitting the purchased-service charge.
  • Confusing the performing lab with the service facility.

We do not treat the last paid claim as the source for Outside Lab and Charges. It may contain information that was valid then and is no longer valid now.

Before the claim leaves your office

  • Review who performed the service.
  • Follow purchased diagnostic test rules.
  • Enter the charge only when applicable.
  • Verify provider details.
  • Compare the completed claim with the clinical and billing record.
  • Confirm the receiving address or electronic route.
  • Keep a secure copy and proof of submission.

Where software helps—and where it does not

Software is useful for formatting and consistency checks around Outside Lab and Charges, but it cannot create missing documentation or decide a payer-specific value. The source record still controls the claim.

Apply this in software: For a workflow that keeps claim data reusable and reviewable, see the CMS-1500 paper and electronic filing options. Software can enforce format and consistency, but the source record and payer instructions still control the claim.
Privacy reminder: Use fictional data for training and printer tests. Claims contain protected information and should be stored, transmitted, printed, and destroyed through approved secure processes.

Written and reviewed by

1500Software Development Team

Covers the software, printing, validation, export, and troubleshooting steps described on this page.

1500Software Claims Review Team

Reviews field placement, provider roles, source records, and practical correction steps.

Reviewed July 26, 2026. Always follow the receiving payer’s current instructions and companion guide.

Official references

These are the national sources we use as a starting point. The receiving payer may add more specific instructions.