Health insurance denial & claim adjustment codes

What health insurance denial code 198 means on your EOB

An authorization existed, but the plan says the care went past what it approved — more visits, more units, or a longer window. The dispute is about what the approval actually said, not whether one existed.

What usually causes it

• The approved number of visits or units was exceeded.
• The authorization window closed before the later dates of service.
• The approval covered a different code than what was ultimately billed.

The documents that decide it

• The original authorization letter with its exact limits.
• The dates and units actually billed.
• Any request for extension and the plan's response.

What to do next

Get the authorization letter and compare its limits line by line against what was billed. Extensions are frequently available and frequently never requested.

This page explains what a code means. It is information, not advice — it does not tell you whether your specific claim should have been paid, and it is not legal, medical, or insurance advice. Your plan documents and your denial notice govern your situation.