https://ttlc.intuit.com/community/taxes/discussion/difference-between-box-12-code-aa-and-d/01/406017#M167578 Code D refers to contributions to a 401(k) plan. Code AA refers to contributions to a Roth 401(k) plan. Now, that seems to mean that if you have code AA in box 12 you should also have code D as both are types of 401(k) plans. In the case where code D is marked but code AA is not, this means that the contribution was to a Traditional 401(k) plan rather than a Roth? Tue, 04 Jun 2019 20:17:10 GMT jnk7711 2019-06-04T20:17:10Z https://ttlc.intuit.com/community/taxes/discussion/difference-between-box-12-code-aa-and-d/01/406017#M167578 Code D refers to contributions to a 401(k) plan. Code AA refers to contributions to a Roth 401(k) plan. Now, that seems to mean that if you have code AA in box 12 you should also have code D as both are types of 401(k) plans. In the case where code D is marked but code AA is not, this means that the contribution was to a Traditional 401(k) plan rather than a Roth? Tue, 04 Jun 2019 20:17:10 GMT https://ttlc.intuit.com/community/taxes/discussion/difference-between-box-12-code-aa-and-d/01/406017#M167578 jnk7711 2019-06-04T20:17:10Z https://ttlc.intuit.com/community/taxes/discussion/yes-that-is-correct-if-the-letter-code-is-d-then-that/01/406021#M167580 <P>Yes, that is correct. If the letter code is D, then that individual has a traditional 401(k) plan.</P><P> <A href="https://ttlc.intuit.com/replies/3300234" target="_blank">https://ttlc.intuit.com/replies/3300234</A> <BR /> </P><BR /> Tue, 04 Jun 2019 20:17:11 GMT https://ttlc.intuit.com/community/taxes/discussion/yes-that-is-correct-if-the-letter-code-is-d-then-that/01/406021#M167580 RyanH2 2019-06-04T20:17:11Z