Last updated: October 14, 2026
Medical Billing 101 is a free site that explains US medical billing, coding and denials. It is for learning only. It is not legal, medical or billing advice, and it does not replace the payer, CMS or your own expert.
This disclaimer at a glance
- Our pages teach general rules and are not advice for your own case.
- Check every rule with the payer, CMS or the code owner before you act.
- We can’t promise that a claim or appeal will be paid.
Educational use only
The guides, tools and templates here teach how billing rules work. They are not advice for your own claim, practice or bill. Professional advice is guidance from someone who knows your facts, such as a certified coder, a billing consultant or a health care lawyer. For that, talk to one of them.
If you are a patient, follow your doctor’s advice about your care. A billing guide should never be the reason you delay care.
No professional relationship
Using this site or its tools does not make you a client. Reading a page or sending us a question does not create a business, legal or medical relationship with Medical Billing 101 or its author.
Check every rule at the source
Billing rules change often. CPT codes are updated by the AMA each year, ICD-10-CM codes by CMS and the CDC, and payer policies whenever the payer decides. We work to keep each page current, and we link to the source we used. Still, we can’t promise that every page is complete or up to date on the day you read it.
Before you send a claim or an appeal, check the rule with its owner:
| Rule or code | Who owns it | Where to check |
|---|---|---|
| Medicare billing rules | CMS | CMS Internet-Only Manuals and your Medicare contractor |
| Denial and remark codes (CARC, RARC) | X12 | X12 code lists |
| CPT codes | AMA | AMA CPT resources |
| Commercial plan rules | The payer | The payer’s provider manual and policies |
CPT is the AMA’s code set for medical services and procedures. A CARC is a code on the payment notice that says why a claim was paid less or denied.
Tools and templates
Our tools and letter templates give you a starting point. They do not know your full claim. For example, the deadline calculator uses common filing limits, but your payer contract may set a different one. Always check the result and edit any letter before you send it.
Results are not guaranteed
Our denial and appeal guides draw on real billing work. But each outcome depends on the payer, the plan, the claim and the records you send. We can’t promise that any appeal, fix or claim will be paid.
Ads and links
This site shows ads from Google AdSense. Ads pay for hosting and help keep every guide and tool free to use. An ad on a page is not a sign that we back the product. See our privacy policy for how ads use cookies.
We do not use affiliate links today. If we ever do, we will say so on that page, as the FTC’s endorsement guides expect.
We link to other sites, such as CMS.gov and payer sites, so you can check our sources. We are not responsible for what those sites say or how they handle your data.
How we fix mistakes
If you find an error, tell us and we will check it against the source. Our editorial policy explains how we write, check and correct pages.
Contact
For questions about this disclaimer, email info@medicalbilling101.com or use the contact page.