Navigating the CMS 1500 Form: How to Fill It Out and Common Mistakes to Avoid

The CMS 1500 form is a critical part of the revenue cycle for private practices. It’s a standardized way to get reimbursements from Medicare, Medicaid, and many private insurance carriers. Standardized, however, isn't synonymous with easy-to-navigate. Ahead, we’ll dive into the components of the CMS 1500 form, when your practice should use it, and strategies to simplify and speed up your payment reconciliation process.

What Is a CMS 1500 Form?

Healthcare providers use the CMS 1500, a paper claim form, to document key details about the patient, any diagnoses, treatments performed, and associated costs for services rendered. Providers then submit it to Medicare for reimbursement. Some state Medicaid programs and private insurers, as well as Medical Equipment Regional Carriers (DMERCs), also use the CMS 1500. The form was designed by the Centers for Medicare and Medicaid Services to process claims for healthcare services. The National Uniform Claim Committee (NUCC) developed the CMS 1500 in 2001 to standardize how practices reported rendered services to Medicare and other insurers. 

Understanding how and when to fill out this form can improve a practice’s revenue cycle. When the form isn’t filled out properly, reimbursements from insurance providers could be delayed, creating an unpredictable and delayed revenue cycle.

Components of the CMS 1500 Form 

The CMS 1500 form captures key information about services rendered and the patient, as required by the Centers for Medicare & Medicaid Services and some other insurers to process claims. Specific components of the form are:

• Sections 1-13: Documents patient personal details and insurance information. 
• Section 14: Records the date of illness, injury, pregnancy, or medical diagnosis.
• Section 15, 16, and 18: Captures important dates, such as days when someone cannot work, hospitalization stays, and other important dates.
• Section 17: Offers space for a referring physician’s name.
• Section 19-23: Records information related to lab work done, prior authorization, diagnosis, and additional claim information.
• Section 24: The biggest section which captures date of treatment, procedures or services rendered, and associated costs.
• Section 25-33: Captures tax and billing information, the provider’s signature, and total charge information.

What Is a HCFA 1500 Form? 

Before 2001, practices used the HCFA 1500 form to submit Medicare Part B claims. Some other private insurance companies and state Medicaid plans also adopted this form. While no longer in use, some still refer to the HCFA 1500 form and CMS 1500 form interchangeably.

CMS 1500 vs HCFA 1500 Forms

The CMS 1500 form is the current standard and should be used. The HCFA 1500 has been archived and shouldn’t be submitted to insurance providers. Both the CMS 1500 and HCFA 1500 aim to foster a standardized method to capture claims, ideally improving revenue cycles in the process. Since the CMS 1500 form is the preferred form, it’s regularly updated to implement necessary changes, such as adding new diagnosis codes or categories required by evolving healthcare regulations.

How to Fill Out the CMS 1500 Form

The CMS 1500 form can be handwritten or completed electronically. The latter is recommended since it’s faster and reduces the likelihood of errors that may cause a claim to be rejected. Additionally, some insurers are transitioning to online submittals only. Medicare, for example, exclusively accepts electronic forms since the technology they use to read these forms cannot process handwritten information. 

Importance of CMS 1500 Form in Medical Billing 

While the CMS 1500 can be a tedious administrative form to complete, it can have a significant impact on your practice’s bottom line. One study published in World Neurosurgery found that successfully completing and submitting CMS 1500 forms in a timely manner led to increased fiscal viability for practices.

Comprehension of the CMS 1500 also improves practice operations. Practices that efficiently fill out and submit this form, for example, may have shorter payment reconciliation cycles and spend less time on administrative work, creating more availability for patient engagement and practice development. 

When choosing a technology system to help manage electronic completion and submission of CMS 1500, you want to make sure you choose what best fits your practice’s needs. Bay Eye Clinic in Oregon had an electronic health records system which was difficult for staff to use but switched to an ophthalmology-specific EHR. Their new technology provider offered robust training to ensure staff were informed on how to use the platform to increase efficiency with common compliance and regulatory requirements.

What Is the Final Step in Processing CMS 1500 Claims?

After a form is completed, it must be submitted to the insurance provider. Depending on the specific payor, this can be done electronically or via mail. Medicare, however, only accepts claims electronically. Claims must also be submitted via a HIPAA-complaint delivery method. The most effective way to ensure compliance is to invest in an EHR that is compliant with HIPAA, the Cures Act, and other healthcare regulations. After submitting, the insurer reviews the form and approves or denies it. Once approved, payment is issued to the practice.

2025 Updates to the CMS 1500 Form

Starting in 2025, all claims must be submitted electronically to Medicare. Many other insurance providers have a similar regulation or are moving to electronic-only submissions by the end of 2025. The form itself, however, has remained the same since 2012, and CMS has not indicated any plans to change the form in the near future. 

5 Common Mistakes and How to Avoid Them

The CMS 1500 is crucial to running an efficient, financially savvy practice. Here are five common mistakes practices make when submitting CMS 1500 claims and strategies to avoid each. 

1. Selecting the Wrong Form

Before submitting an insurance claim, assess if the CMS 1500 or the UB-04 is the proper form.  To know which one to use, check with the insurance provider or other company type that you’re submitting a claim to. When a claim is for Medicare or Medicaid, the CMS 1500 is almost always required, though there could be some state-specific variations for Medicaid. The UB-04 is another standard claim form used by some private insurance providers, hospitals, and ancillary/hospital service coordinators.

2. Opting for Paper CMS 1500 Forms

While the CMS 1500 can be completed by hand, paper billing is time-consuming, increases the chance for errors, and is not accepted by all carriers. In fact, many insurance carriers, including Medicare, are implementing new technologies that can only read forms completed electronically.

3. Missing Hidden Sections

The CMS 1500 is compact, and some sections are easy to miss. Others are optional, meaning an automated system or an administrative staff member may be confused about whether to complete them. 

Optional parts of the CMS 1500 include:

• Section 9
• Section 17
• Section 19 (required but answers vary based on condition and treatment)
• Section 21 (subsections A-L are not always completed)
• Section 16
• Section 18
• Section 22

Designating a staff member to review all forms before submitting enables your practice to flag any missing or hidden sections. Additionally, working with an EHR provider mitigates the risk of rejected claims.

4. Not Getting Industry-Specific Recommendations

While the CMS 1500 is used across industries, an ophthalmology practice will probably complete the form differently than a cardiologist. An EHR provider who specializes in your practice type can answer any industry-specific questions about the CMS 1500. Ideally, they should also offer resources or training sessions on industry regulations.

5. Not Automating the Process

While you can manually enter all the information onto an electronic or physical CMS 1500 form, many modern EHRs utilize artificial intelligence (AI) and other technologies to automatically fill in certain categories, such as the patient name and date of birth. Automating parts of the CMS 1500 claims process enables your practice to make claims faster while reducing the administrative load.

When filing a CMS 1500 form, one of the best ways to avoid these mistakes is to submit via a certified technology platform like Nextech. Learn how our comprehensive technology platform and support from our team of regulatory and revenue cycle experts can help your practice optimize the CMS 1500 submission process and maintain maximum compliance — request a demo.

Frequently Asked Questions

How many lines can I add to CMS 1500 form?

There are six lines for different services, procedures, or supplies rendered on the CMS 1500 form. Each service, procedure, or supply requires one line.

How to add attachment to CMS 1500 form​?

The exact instructions for adding an attachment to a CMS 1500 depend on who you’re submitting the form to (Medicare, a state Medicaid agency, or a private provider). 

Many carriers also require attachments with the patient’s name and insurance ID number. 

Where can I add a denied claim EOB on CMS 1500?

A denied claim EOB comes with a number from the carrier that should be placed in section 11 on the CMS 1500. Most providers will also require you to attach supporting documentation.  

How many diagnoses can be reported on the CMS 1500? 

Up to 12 diagnoses can be reported in section 21A-21L. For each diagnosis, detail the patient’s condition and include the ICD code. 

Where does taxonomy code go on CMS 1500​?

Place the taxonomy code in section 33B on the CMS 1500 form. This code describes the provider’s area of specialization or classification. 

Is the CMS 1500 form only used for outpatient services?

The CMS 1500 form can be used for outpatient services as well as some inpatient ones. When to utilize the CMS 1500 depends on the insurance provider, with Medicare, state Medicaid agencies, and private insurance companies having slightly different processes for this form. 

What is the difference between CMS 1500 and 1450?

The CMS 1450, also referred to as the UB-04, covers in-patient services, such as surgery, radiology, laboratory, or other facility services. In contrast, the CMS 1500 is used for Medicare Part B claims, which are mostly out-patient services, though select in-patient services may also require this form. 

Where is the carrier block located on the CMS 1500? 

The carrier block is located on page one in the top right-hand corner of the CMS 1500. Practices should enter the address of the insurance carrier in this block.

Can CMS 1500 forms be handwritten?

While you can technically handwrite the CMS 1500, it’s not recommended. For increased efficiency and fewer errors, opt for an electronic health record system that automatically fills in some portions of the form and allows your team to manually edit if necessary before sending.