If you purchase health coverage through the Marketplace, you might be eligible for the premium tax credit. If you’re eligible, advance payments of this credit can help you pay your health insurance premiums. If you wait to get the premium tax credit when you file your tax return, it may increase your refund.
You must file a tax return to claim the premium tax credit. You will figure your credit on Form 8962, Premium Tax Credit (PTC). You must complete this form to claim the premium tax credit and reconcile any advance credit payments with the premium tax credit you are eligible to claim on your return. Your Form 1095-A, Health Insurance Marketplace Statement, which you receive from the Health Insurance Marketplace, provides information you will need when completing Form 8962. If Form 1095-A was lost, never received, or is incorrect, contact your Marketplace directly for a copy. The IRS does not issue Form 1095-A and cannot provide you with a copy.
The premium tax credit is a refundable tax credit. This means that if the amount of the credit is more than the amount of your tax liability, you will receive the difference as a refund. If you owe no tax, you can get the full amount of the credit as a refund.
If you receive advance payments of the credit, you will subtract those payments from the premium tax credit that you calculate using Form 8962. If the premium tax credit computed is more than the advance credit payments, the difference will increase your refund or lower the amount of tax owed. If the advance credit payments are more than the premium tax credit, the difference will increase the amount of your tax liability and result in either a smaller refund or taxes owed. Filing your return without reconciling your advance payments in this manner will delay your refund and may affect future advance credit payments.
See the IRS info here for basic information about PTC.
See the IRS FAQ here for additional information on PTC.