Box 1a on the CMS-1500 is where the insured's ID number is entered as shown on their insurance ID card.
To change the insured's ID on the claim form:
- Navigate to the patient's Intake > Insurance tab.
- Click into the insurance set primary payer for the claim.
- Go to the Policy Holder tab.
- Click Edit.
- Edit the Insurance ID field.
- Click Save.
Loop 2010BA, Segment NM109