How do I choose the right E/M level in 2026?

Select on medical decision making or on total time on the date of the encounter. Document the number and complexity of problems addressed, data reviewed, and risk — history and exam no longer drive level selection for office visits.

When should I use modifier 25?

When a significant, separately identifiable E/M service is performed on the same day as a procedure. The note must stand on its own for the E/M portion; appending 25 to bypass a bundling edit without that documentation is a common audit finding.

What is an NCCI edit?

A CMS-published pair of codes that should not normally be billed together. Some pairs allow a modifier to override the edit when the services were genuinely separate; others never allow it.

How often do CPT codes change?

Annually on January 1, with additions, deletions, and revisions each cycle. ICD-10-CM updates October 1. Using a deleted code produces an immediate rejection.

Who is responsible if a code is wrong — the coder or the physician?

The billing provider carries legal responsibility for the claim, which is why documentation and coder queries matter. In practice, a query process that resolves ambiguity before submission protects both.

Coding

Medical Coding Guidelines, Modifiers and Code Lookup

Code the encounter that happened, in the way the payer can read.

Coding is translation under rules. The clinical note describes what happened; CPT, HCPCS, and ICD-10-CM describe it in a form a payer's adjudication engine can price. Most coding disputes are not about honesty — they are about whether the documentation supports the code that was billed.

Three things generate the majority of coding denials. Modifiers used incorrectly or omitted where they were required. E/M levels that the note does not support under the current medical decision making or time rules. And NCCI edits that bundle a procedure into another one performed the same day, where the modifier that would unbundle it is either missing or unjustified.

This section is organized so you can go straight to the rule you need: general guidelines by code family, a modifier reference covering the modifiers that actually appear on claims, evaluation and management level selection with documentation examples, and a searchable index of individual CPT codes with their common denial patterns.

Coding sets change every year — CPT in January, ICD-10-CM in October, and quarterly NCCI edit updates in between. Where a rule has a version, the articles say which year they describe.

Explore this section

Coding Guidelines
CPT, HCPCS and ICD-10 rules, NCCI edits, and documentation standards.
Modifiers
Every modifier that regularly appears on claims, with correct usage.
E/M Coding
Level selection by MDM or time, split/shared visits, and prolonged services.

Frequently asked questions

How do I choose the right E/M level in 2026?: Select on medical decision making or on total time on the date of the encounter. Document the number and complexity of problems addressed, data reviewed, and risk — history and exam no longer drive level selection for office visits.
When should I use modifier 25?: When a significant, separately identifiable E/M service is performed on the same day as a procedure. The note must stand on its own for the E/M portion; appending 25 to bypass a bundling edit without that documentation is a common audit finding.
What is an NCCI edit?: A CMS-published pair of codes that should not normally be billed together. Some pairs allow a modifier to override the edit when the services were genuinely separate; others never allow it.
How often do CPT codes change?: Annually on January 1, with additions, deletions, and revisions each cycle. ICD-10-CM updates October 1. Using a deleted code produces an immediate rejection.
Who is responsible if a code is wrong — the coder or the physician?: The billing provider carries legal responsibility for the claim, which is why documentation and coder queries matter. In practice, a query process that resolves ambiguity before submission protects both.

More on coding

Modifier rules, E/M level selection, NCCI edits and annual code set changes, covered article by article.

Browse CPT codes