Why will it not identify me as head of household when, as a single person, I had guardianship of 2 kids for 351 days, who are listed as my dependents?

The IRS defines HOH using three core tests. These are consistent across authoritative sources, including IRS Publication 501 and tax guidance from major preparers.

1. You must be unmarried or considered unmarried on the last day of the year

• You meet this if:
• You were legally single, or
• You were separated and lived apart from your spouse for the last 6 months of the year.

2. You must have paid more than half the cost of keeping up your home. 

3. You must have a qualifying person who lived with you more than half the year

1. This is the most complex part. A qualifying person must meet the IRS relationship and residency tests. According to IRS rules and tax guidance: 

• A qualifying person can be your child, stepchild, foster child placed by a court or agency, sibling, parent, or certain other relatives.
• A dependent parent does not need to live with you, but children and most other dependents do

The IRS relationship test is stricter than the dependency test. You can claim someone as a dependent even if they are not related to you, but that does not make them a qualifying person for HOH.

1. A child under your guardianship qualifies you for HOH only if:

• They are your biological, adopted, or stepchild, or 
• They are a foster child placed with you by a court or government agency.
• If the children are not related to you and your guardianship order does not classify them as foster children, the IRS does not treat them as qualifying persons for HOH—even if they lived with you 351 days and you provided all support.

These are the most common reasons why you weren't able to claim the Head of Household status. If you qualify, go through all your qualifying answers to your questions and pinpoint those that may prevent you from claiming this status.