I need to change from a fulltime student to a part time student how does that affect my return

[Hal_Al]

It depends.  What tax attributes are you concerned with?

As long as you are  half time or more, you can still claim a tuition credit.

If you are currently a dependent, that might change.  

There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, full time student status, a relationship test and residence test. The support test is different for each type. The support test, for a QC, is only that the child didn't provide more than half his own support. The support test for a Qualifying Relative is that the taxpayer provided more than half the relative's support.

A child of a taxpayer can still be a “Qualifying Child” (QC) dependent, regardless of his/her income, if:

1. He is under age 19, or under 24 if a full time student for at least 5 months of the year, or is totally & permanently disabled
2. He did not provide more than 1/2 his own support. Scholarships are excluded from the support calculation
3.  He lived with the parent (including temporary absences such as away at school) for more than half the year

A person can still be a Qualifying relative dependent, if not a Qualifying Child, if he meets the 6 tests for claiming a dependent:

1. Closely Related OR live with the taxpayer ALL year
2. His/her gross taxable income for the year must be less than $4300 (2020).
3. The taxpayer must have provided more than 1/2 his support

In either case:

4. He must be a US citizen or resident of the US, Canada or Mexico
5. He must not file a joint return with his spouse or be claiming a dependent of his own
6. He must not be the qualifying child of another taxpayer

[DawnC]

To claim the American Opportunity Credit, you have to be an eligible student enrolled at least half-time.  An eligible student is defined as a student who:

• Is enrolled at least half-time in a program leading to a degree, certificate, or other recognized credential
• Had at least one academic period beginning during the year
• Didn't claim the American Opportunity Tax Credit for more than three previous years
• Didn't complete the first four years of post-secondary education before the beginning of the year

TurboTax will ask you questions about your enrollment status when you start the Education section under Deductions and Credits.

And you can't take the Saver's Credit if you are a full-time student.    You can go back and check your answers to your enrollment status by visiting the Retirement Savings Contribution Credit section, also under Deductions and Credits.