CMS Pub. 100-04, ch. 3, § 190.5.2

According to the ICD Official Guidelines for Coding and Reporting, when a principal

diagnosis code has a Code First notation, the provider follows the applicable coding

convention, which requires the underlying condition (etiology) to be sequenced first,

followed by the manifestation due to the underlying condition. Therefore, CMS considers

Code First diagnoses to be the principal diagnosis. The submitted claim goes through the

IPF PPS claims processing system that identifies the principal diagnosis code as non-psychiatric and searches only the first “secondary” code for a psychiatric code to assign

the DRG/MS-DRG in order to pay Code First claims properly.

For more coding guidance, refer to the ICD-9-CM Official Guidelines for Coding and

Reporting which can be located on the CDC Web site at:

http://www.cdc.gov/nchs/icd/icd9cm.htm

The ICD-10-CM Official Guidelines are posted on the CDC’s website at:

http://www.cdc.gov/nchs/icd/icd10cm.htm

The most current Code First list is posted on the IPF PPS Web site at:

www.cms.gov/InpatientPsychFacilPPS. Select Tools and Worksheets from the column at

the left.

Code First Example - ICD-9-CM

Diagnosis code 294.11 “Dementia in Conditions Classified Elsewhere with Behavioral

Disturbances” is designated as “NOT ALLOWED AS PRINCIPAL DX” code.

Four digit code 294.1 “Dementia in Conditions Classified Elsewhere”, is designated as a

Code First diagnosis indicating that all 5 digit diagnosis codes that fall under the 294.1

category (codes 294.10 and 294.11) must follow the Code First rule. The 3 digit code 294

“Persistent Mental Disorders Due to Conditions Classified Elsewhere” appears in the ICD-

9-CM as follows:

294 - PERSISTENT MENTAL DISORDERS DUE TO CONDITIONS CLASSIFIED

ELSEWHERE

294.1 - Dementia in Conditions Classified Elsewhere

Code First any underlying physical condition, as:

Dementia in:

Alzheimer’s disease (331.0)

Cerebral lipidosis (330.1)

Dementia with Lewy bodies (331.82)

Dementia with Parkinsonism (331.81)

Epilepsy (345.0 - 345.9)

Frontal dementia (331.19)

Frontotemporal dementia (331.19)

General paresis [syphilis] (094.1)

Hepatolenticular degeneration (275.1)

Huntington’s chorea (333.4)

Jacob-Creutzfeldt disease (046.1)

Multiple sclerosis (340)

Pick's disease of the brain (331.11)

Polyarteritis nodosa (446.0)

Syphilis (094.1)

294.10 Dementia in Conditions Classified Elsewhere Without Behavioral Disturbances

NOT ALLOWED AS PRINCIPAL DX

294.11 Dementia in Conditions Classified Elsewhere With Behavioral Disturbances

NOT ALLOWED AS PRINCIPAL DX

According to Code First requirements, the provider would code the appropriate physical

condition first, for example, 333.4 “Huntington’s Chorea” as the principal diagnosis code

and 294.11 “Dementia In Conditions Classified Elsewhere With Behavioral Disturbances”

as a secondary diagnosis or comorbidity code on the patient claim.

The purpose of this example is to demonstrate proper coding for a Code First situation.

However, in this case, the principal diagnosis groups to one of the 15 DRGs, or 17 MS-DRGs, for which CMS pays an adjustment. Had the diagnosis code grouped to a non-psychiatric DRG/MS-DRG, the PRICER would search the first of the other diagnosis

codes for a psychiatric code listed in the Code First list in order to assign a DRG

adjustment.

Code First Example - ICD-10-CM

Diagnosis code F02.81 “Dementia in other diseases classified elsewhere with behavioral

disturbance” is designated as “NOT ALLOWED AS PRINCIPAL DX” code.

The three digit code F02 “Dementia in other diseases classified elsewhere”, is designated

as a Code First diagnosis indicating that all diagnosis codes that fall under the F02

category (codes F02.80 and F02.81) must follow the Code First rule. The 3 digit code F02

“Dementia in other diseases classified elsewhere” appears in the ICD-10-CM as follows:

F02 Dementia in other diseases classified elsewhere

Code first the underlying physiological condition, such as:

Alzheimer's (G30.0 - G30.9)

cerebral lipidosis (E75.4)

Creutzfeldt-Jakob disease (A81.0 - A81.09)

dementia with Lewy bodies (G31.83)

epilepsy and recurrent seizures (G40 - G40.919)

frontotemporal dementia (G31.09)

hepatolenticular degeneration (E83.0)

human immunodeficiency virus [HIV] disease (B20)

hypercalcemia (E83.52)

hypothyroidism, acquired (E00 - E03.9)

intoxications (T36 - T65)

Jakob-Creutzfeldt disease (A81.00 - A81.09)

multiple sclerosis (G35)

neurosyphilis (A52.17)

niacin deficiency [pellagra] (E52)

Parkinson's disease (G20)

Pick's disease (G31.01)

polyarteritis nodosa (M30.0)

systemic lupus erythematosus (M32 - M32.9)

trypanosomiasis (B56 - B57.39)

vitamin B deficiency (E53.8)

F02.80 Dementia in other diseases classified elsewhere without behavioral disturbance

NOT ALLOWED AS PRINCIPAL DX

F02.81 Dementia in other diseases classified elsewhere with behavioral disturbance

NOT ALLOWED AS PRINCIPAL DX

According to Code First requirements, the provider would code the appropriate physical

condition first, for example, G20 “Parkinson’s disease” as the principal diagnosis code

and F02.81 “Dementia in other diseases classified elsewhere with behavioral disturbance”

as a secondary diagnosis or comorbidity code on the patient claim.