Which guidelines must be used for a date of service when coding?

• A. The ICD-10-CM guidelines in effect on the current date
• B. The ICD-10-CM guidelines in effect on the DOS date
• C. The ICD-10-CM guidelines in effect on the provider's preference
• D. The ICD-10-CM guidelines in effect on the DOS date of service being coded

Answer: (D)

Guidelines used for coding are date-specific: you apply the ICD-10-CM guidelines that were in effect on the date of service for the item being coded. These guidelines can change from year to year, and coding rules that applied to a service on its date may differ from rules in effect today. If you used the current date’s guidelines for a service from a past date, you could miscode because the standards at that earlier time might have been different. The provider’s preference doesn’t determine which rules apply, and for each service, you use the version of the guidelines that matches its actual date of service. If multiple services are documented on different dates, each one should follow the guidelines in effect for its specific date.